Category Archives: Conversion Rate Optimization

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Smashing Book 6 Is Here: New Frontiers In Web Design




Smashing Book 6 Is Here: New Frontiers In Web Design

Vitaly Friedman



Imagine you were living in a perfect world. A world where everybody has fast, stable and unthrottled connections, reliable and powerful devices, exquisite screens, and capable, resilient browsers. The screens are diverse in size and pixel density, yet our interfaces adapt to varying conditions swiftly and seamlessly. What a glorious time for all of us — designers, developers, senior Webpack configurators and everybody in-between — to be alive, wouldn’t you agree?

Well, we all know that the reality is slightly more nuanced and complicated than that. That’s why we created Smashing Book 6, our shiny new book that explores uncharted territories and seeks to discover new reliable front-end and UX techniques. And now, after 10 months of work, the book is ready, and it’s shipping. Jump to table of contents and get the book right away.


Smashing Book 6: New Frontiers in Web Design

eBook

$19Get the eBook

PDF, ePUB, Kindle. Free for Smashing Members.

Hardcover

$39Get the Print (incl. eBook)

Printed, quality hardcover. Free airmail shipping worldwide.

About The Book

Finding your way through front-end and UX these days is challenging and time-consuming. But frankly, we all just don’t have time to afford betting on a wrong strategy. Smashing Book 6 sheds some light on new challenges and opportunities, but also uncovers new traps and pitfalls in this brave new front-end world of ours.

Our books aren’t concerned with short-living trends, and our new book isn’t an exception. Smashing Book 6 is focused on real challenges and real front-end solutions in the real world: from accessible apps to performance to CSS Grid Layout to advanced service workers to responsive art direction. No chit-chat or theory. Things that worked, in actual projects. Jump to table of contents.


Smashing Book 6


The Smashing Book 6, with 536 pages on real-life challenges and opportunities on the web. Photo by our dear friend Marc Thiele. (Large preview)

In the book, Laura and Marcy explore strategies for maintainable design systems and accessible single-page apps with React, Angular etc. Mike, Rachel and Lyza share insights on using CSS Custom Properties and CSS Grid in production today. Yoav and Lyza take a dive deep into performance patterns and service workers in times of Progressive Web Apps and HTTP/2.


Inner design of the Smashing Book 6.


Inner design of the Smashing Book 6. Designed by one-and-only Chiara Aliotta. Large view.

Ada, Adrian and Greg explore how to design for watches and new form factors, as well as AR/VR/XR, chatbots and conversational UIs. The last chapter will guide you through some practical strategies to break out of generic, predictable, and soulless interfaces — with dozens of examples of responsive art direction. But most importantly: it’s the book dedicated to headaches and solutions in the fragile, inconsistent, fragmented and wonderfully diverse web we find ourselves in today.

Table Of Contents

Want to peek inside? Download a free PDF sample (PDF, ca. 21 MB) with a chapter on bringing personality back to the web by yours truly. Overall, the book contains 10 chapters:

  1. Making Design Systems Work In Real-Life
    by Laura Elizabeth
  2. Accessibility In Times Of Single-Page Applications
    by Marcy Sutton
  3. Production-Ready CSS Grid Layouts
    by Rachel Andrew
  4. Strategic Guide To CSS Custom Properties
    by Mike Riethmueller
  5. Building An Advanced Service Worker
    by Lyza Gardner
  6. Loading Assets On The Web
    by Yoav Weiss
  7. Conversation Interface Design Patterns
    by Adrian Zumbrunnen
  8. Building Chatbots And Designing For Watches
    by Greg Nudelman
  9. Cross Reality And The Web (AR/VR)
    by Ada Rose Cannon
  10. Bringing Personality Back To The Web (free PDF sample, 21MB)
    by Vitaly Friedman
Laura Elizabeth
Marcy Sutton
Rachel Andrew
Mike Riethmuller
Lyza Danger Gardner
Yoav Weiss
Adrian Zumbrunnen
Greg Nudelman
Ada Rose Edwards
Vitaly Friedman
From left to right: Laura Elizabeth, Marcy Sutton, Rachel Andrew, Mike Riethmuller, Lyza D. Gardner, Yoav Weiss, Adrian Zumbrunnen, Greg Nudelman, Ada Rose Edwards, and yours truly.

  • 536 pages. Quality hardcover + eBook (PDF, ePUB, Kindle).
    Published late September 2018.
  • Written by and for designers and front-end developers.
    Designed with love from Italy by Chiara Aliotta.
  • Free airmail worldwide shipping from Germany.
    Check delivery times for your country.
  • If you are a Smashing Member, don’t forget to apply your Membership discount.
  • Good enough? Get the book right away.

Smashing Book 6: Covers of Chapter 1 and Chapter 10

eBook

$19Get the eBook

PDF, ePUB, Kindle. Free for Smashing Members.

Hardcover

$39Get the Print (incl. eBook)

Printed, quality hardcover. Free airmail shipping worldwide.

About The Designer

Chiara AliottaThe cover was designed with love from Italy by one-and-only Chiara Aliotta. She founded the design studio Until Sunday and has directed the overall artistic look and feel of different tech companies and not-for-profit organizations around the world. We’re very happy that she gave Smashing Book 6 that special, magical touch.

Behind The Scenes Of The Design Process

We asked Chiara to share some insights into the design process of the cover and the interior design and she was very kind to share some thoughts with us:

“It all started with a few exchanges of emails and a Skype meeting where Vitaly shared his idea of the book and the general content. I had a lot of freedom, which is always exciting and scary at the same time. The only bond (if we want to call it like this) was that the “S” of Smashing Magazine should be the main protagonist of the cover, reinvented and creatively presented as per all the other previous Smashing Books.




The illustration on paper. The cover sketched on paper. Also check the close-up photo. (Large preview)

I worked around few keywords that Vitaly was using to describe the book during our meetings and then developed an idea around classical novels of adventure where the main hero leaves home, encounters great hazards, risks, and then eventually returns wiser and/or richer than he/she was before.

So I thought of Smashing Book 6 as a way to propose this basic and mythic structure under a new light: through the articles of this book, the modern web designer will be experiencing true and deep adventures.

I imagined the “S” as an engine, the starting point of this experience, from where different worlds were creating and expanding. So the cover was the map of these uncharted territories that the book explores.

Every element on the cover has a particular meaning that constructs the S
Every element on the cover has a particular meaning that constructs the S. Large view.

I am a person who judges books by its cover and having read some of the chapters and knowing some of the well-established writers, I wanted to honour its content and their work by creating a gorgeous cover and chapter illustrations.

For this edition of Smashing Book, I imagined a textile cover in deep blue, where the graphic is printed using a very old technique, the hot gold foil stamping.

Together with Markus, part of the Smashing Magazine team and responsible for the publishing of all the Smashing Books, we worked closely to choose the final details of the binding and guarantee an elegant and sophisticated result, adding a touch of glam to the book.




Smashing Book 6 comes wrapped with a little bookmark. Photo by our dear friend Marc Thiele.

As a final touch, I added a paper wrap around the book that invites the readers to “unlock their adventure”, suggesting a physical action: the reader needs to tear off the paper before starting reading the book.
And for this only version, we introduced a customise Smashing Magazine bookmark, also in printed on gold paper. Few more reasons to prefer the paperback version over the digital ones!”

A huge round of applause to Chiara for her wonderful work and sharing the thoughts with us. We were remarkably happy with everything from design to content. But what did readers think? Well, I’m glad that you asked!




Sketches for chapter illustrations. (Large preview)

Feedback and Testimonials

We’ve sent the shiny new book to over 200 people to peek through and read, and we were able to gather some first insights. We’d love to hear your thoughts, too!

“Web design is getting pretty darned complicated. The new book from SmashingMag aims to bring the learning curve down to an accessible level.”

Aaron Walter, InVision

“Just got the new Smashing Book 6 by SmashingMag. What a blast! From CSS Grid Layout, CSS Custom Properties and service workers all the way to the HTTP/2 and conversational interfaces and many more. I recommend it to all the people who build interfaces.”

Mihael Tomić, Osijek, Croatia

“The books published by SmashingMag and team are getting better each time. I was thrilled to be able to preview it… EVERY CHAPTER IS GOOD! Having focused on a11y for much of my career, Marcy Sutton’s chapter is a personal favorite.”

Stephen Hay, Amsterdam, Netherlands


Smashing Book 6, a thank-you page


The Smashing Book 6, with 536 pages on real-life challenges and solutions for the web. Huge thank-you note to the smashing community for supporting the book and out little magazine all these years. (Large preview)

Thank You For Your Support!

We’re very honored and proud to have worked with wonderful people from the industry who shared what they’ve learned in their work. We kindly thank all the hard-working people involved in making this book reality. We kindly thank you for your ongoing support of the book and our little magazine as well. It would be wonderful if you could mention the book by any chance as well in your social circles and perhaps link to this very post.

We’ve also prepared a little media kit .zip with a few photos and illustrations that you could use if you wanted to — just sayin’!

We can’t wait to hear your thoughts about the book! Happy reading, and we hope that you’ll find the book as useful as we do. Just have a cup of coffee (or tea) ready before you start reading, of course, stay smashing and… meow!


Smashing Book 6: New Frontiers in Web Design

eBook

$19Get the eBook

PDF, ePUB, Kindle. Free for Smashing Members.

Hardcover

$39Get the Print (incl. eBook)

Printed, quality hardcover. Free airmail shipping worldwide.

Smashing Editorial
(ra, il)


Continued here:  

Smashing Book 6 Is Here: New Frontiers In Web Design

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How to Calculate Your Landing Page Conversion Rate (And Increase It)

landing-page-conversion-rate-introduction

A landing page represents an opportunity. Your prospect or lead will either take advantage of it or they won’t. The landing page conversion rate tells you how well you’re doing. Some websites have one or two landing pages, while others have dozens. It all depends on how many products or services you sell and what referral source sends you the most traffic. For instance, if you get tons of traffic from Facebook and Instagram Ads, you might have a landing page for each of those referral sources. You’ll want to optimize each page to reflect the visual aesthetic and copy…

The post How to Calculate Your Landing Page Conversion Rate (And Increase It) appeared first on The Daily Egg.

Excerpt from:  

How to Calculate Your Landing Page Conversion Rate (And Increase It)

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The Importance Of Manual Accessibility Testing




The Importance Of Manual Accessibility Testing

Eric Bailey



Earlier this year, a man drove his car into a lake after following directions from a smartphone app that helps drivers navigate by issuing turn-by-turn directions. Unfortunately, the app’s programming did not include instructions to avoid roads that turn into boat launches.

From the perspective of the app, it did exactly what it was programmed to do, i.e. to find the most optimal route from point A to point B given the information made available to it. From the perspective of the man, it failed him by not taking the real world into account.

The same principle applies for accessibility testing.

Designing For Accessibility And Inclusion

The more inclusive you are to the needs of your users, the more accessible your design is. Let’s take a closer look at the different lenses of accessibility through which you can refine your designs. Read article →

Automated Accessibility Testing

I am going to assume that you’re reading this article because you’re interested in learning how to test your websites and web apps to ensure they’re accessible. If you want to learn more about why accessibility is necessary, the topic has been covered extensively elsewhere.

Automated accessibility testing is a process where you use a series of scripts to test for the presence, or lack of certain conditions in code. These conditions are dictated by the Web Content Accessibility Guidelines (WCAG), a standard by the W3C that outlines how to make digital experiences accessible.

For example, an automated accessibility test might check to see if the tabindex attribute is present and if its value is greater than 0. The pseudocode would be something like:


A flowchart that asks if the tabindex value is present. If yes, it asks if the tabindex value is greater than 0. If it is greater than zero, it fails. If not, it passes. If no tabindex value is present, it also passes.

Failures can then be collected and used to generate reports that disclose the number, and severity of accessibility issues. Certain automated accessibility products can also integrate as a Continuous Integration or Continuous Deployment (CI/CD) tool, presenting just-in-time warnings to developers when they attempt to add code to a central repository.

These automated programs are incredible resources. Modern websites and web apps are complicated things that involve hundreds of states, thousands of lines of code, and complicated multi-screen interactions. It’d be absurd to expect a human (or a team of humans) to mind all the code controlling every possible permutation of the site, to say nothing of things like regressions, software rot, and A/B tests.

Automation really shines here. It can repeatedly and tirelessly pour over these details with perfect memory, at a rate far faster than any human is capable of.

However…

Automated accessibility tests aren’t a turnkey solution, nor are they a silver bullet. There are some limitations to keep in mind when using them.

Thinking To Think Of Things

One of both the best and worst aspects of the web is that there are many different ways to implement a solution to a problem. While this flexibility has kept the web robust and adaptable and ensured it outlived other competing technologies, it also means that you’ll sometimes see code that is, um, creatively implemented.

The test suite is only as good as what its author thought to check for. A naïve developer might only write tests for the happy path, where everyone writes semantic HTML, fault-tolerant JavaScript, and well-scoped CSS. However, this is the real world. We need to acknowledge that things like tight deadlines, unfamiliarity with the programming language, atypical user input, and sketchy 3rd party scripts exist.

For example, the automated accessibility testing site Tenon.io wisely includes a rule that checks to see if a form element has both a label element and an aria-label associated with it, and if the text strings for both declarations differ. If they do, it will flag it as an issue, as the visible label may be different than what someone would hear if they were navigating using a screen reader.

If you’re not using a testing service that includes this rule, it won’t be reported. The code will still “pass”, but it’s passing by omission, not because it’s actually accessible.

State

Some automated accessibility tests cannot parse the various states of interactive content. Critical parts of the user interface are effectively invisible to automation unless the test is run when the content is in an active, selected, or disabled state.

By interactive content, I mean things that the user has yet to take action on, or aren’t present when the page loads. Unopened modals, collapsed accordions, hidden tab content and carousel slides are all examples.

It takes sophisticated software to automatically test the various states of every component within a single screen, let alone across an entire web app or website. While it is possible to augment testing software with automated accessibility checks, it is very resource-intensive, usually requiring a dedicated team of engineers to set up and maintain.

“Valid” Markup

Accessible Rich Internet Applications (ARIA) is a set of attributes that extend HTML to allow it to describe interaction in a way that can be better understood by assistive technologies. For example, the aria-expanded attribute can be toggled by JavaScript to programmatically communicate if a component is in an expanded (true) or collapsed (false) state. This is superior to toggling a CSS class like .is-expanded, where the update in state is only communicated visually.

Just having the presence of ARIA does not guarantee that it will automatically make something accessible. Unfortunately, and in spite of its first rule of use, ARIA is commonly misunderstood, and consequently abused. A lot of off-the-shelf code has this problem, perpetuating the issue.

For example, certain ARIA attributes and values can only be applied to certain elements. If incorrectly applied, assistive technology will ignore or misreport the declaration. Certain roles, known as Abstract Roles, only exist to set up the overall taxonomy and should never be placed in markup.

<button role="command">Save</button>

<!-- Never do this -->

To further complicate the issue, support for ARIA is varied across browsers. While an attribute may be used appropriately, the browser may not communicate the declared role, property, or state to assistive technology.

There is also the scenario where ARIA can be applied to an element and be valid from a technical standpoint, yet be unusable from an assistive technology perspective. For example:

<h1 aria-hidden=“true”>
  Tired of unevenly cooked asparagus? Try this tip from the world’s oldest cookbook.
</h1>

This one Weird Trick.

The aria-hidden declaration will remove the presence of content from assistive technology, yet allow it to be still rendered visibly on the page. It’s a problematic pattern.

Headings — especially first-level headings — are vital in communicating the purpose of a page. If a person is using assistive technology to navigate, the aria-hidden declaration applied to the h1 element will make it difficult for them to quickly determine the page’s purpose. It will force them to navigate around the rest of the page to gain context, an annoying and labor-intensive process.

Some automated accessibility tests may scan the code and not report an error since the syntax itself is valid. The automation has no way of knowing the greater context of the declaration’s use.

This isn’t to say you should completely avoid using ARIA! When authored with care and deliberation, ARIA can fix the gaps in accessibility that sometimes plague complicated interactions; it provides some much-needed context to the people who rely on assistive technology.

Much-Needed Context

As the soggy car demonstrates, computers are awful at understanding the overall situation of the outside world. It’s up to us humans to be the ultimate arbiters in determining if what the computer spits out is useful or not.

Debunking

Before we discuss how to provide appropriate context, there are a few common misunderstandings about accessibility work that need to be addressed:

First, not all screen reader users are blind. In addition to all the points Adrian Roselli outlines in his post, some food for thought: the use of voice assistants is on the rise. When’s the last time you spoke to Siri or Alexa?

Second, accessibility is more than just screen readers. The rules outlined in the Web Content Accessibility Guidelines ensure that the largest number of people can read and operate technology, regardless of ability or circumstance.

For example, the rule that stipulates a website or web app needs to be able to work regardless of device orientation benefits everyone. Some people may need to mount their device in a fixed location in a specific orientation, such as in landscape mode on the arm of a wheelchair. Others might want to lie in bed and watch a movie, or better investigate a product photo (pinch and pull zooming will also be helpful to have here).

Third, disabilities can be conditional and can be brought about by your environment. It can be a short-term thing, like rain on your glasses, sleep deprivation, or an allergies-induced migraine. It can also be longer-term, such as a debilitating illness, broken limb, or a depressive episode. Multiple, compounding conditions can (and do) affect individuals.

That all being said, many accessibility fixes that help screen readers work properly also benefit other assistive technologies.

Get Your Feet Wet

Knowing where to begin can be overwhelming. Consider Michiel Bijl’s great advice:

“Before you release a website, tab through it. If you cannot see where you are on the page after each tab; you're not finished yet. #a11y

Tab through a few of the main user flows on your website or web app to determine if all interactive components’ focus states are visually apparent, and if they can be activated via keyboard input. If there’s something you can click or tap on that isn’t getting highlighted when receiving keyboard focus, take note of it. Also pay attention to the order interactive components are highlighted when focused — it should match the reading order of the site.

An obvious focus state and logical tab order go a great way to helping make your site accessible. These two features benefit a wide variety of assistive technology, including, but not limited to, screen readers.

If you need a baseline to compare your testing to, Dave Rupert has an excellent project called A11Y Nutrition Cards, which outlines expected behavior for common interactive components. In addition, Scott O’Hara maintains a project called a11y Styled Form Controls. This project provides examples of components such as switches, checkboxes, and radio buttons that have well-tested and documented support for assistive technology. A clever reader might use one of these resources to help them try out the other!


A screenshot of homepage for the a11y Styled Form Controls website placed over a screenshot of the Nutrition Cards for Accessible Components website.


(Large preview)

The Fourth Myth

With that out of the way, I’m going to share a fourth myth with you: not every assistive technology user is a power user. Like with any other piece of software, there’s a learning curve involved.

In her post about Aaptiv’s redesign, Lisa Zhu discovers that their initial accessibility fix wasn’t intuitive. While their first implementation was “technically” correct, it didn’t line up with how people who rely on VoiceOver actually use their devices. A second solution simplified the interaction to better align with their expectations.

Don’t assume that just because something hypothetically functions that it’s actually usable. Trust your gut: if it feels especially awkward, cumbersome, or tedious to operate for you, chances are it’ll be for others.

Dive Right In

While not every accessibility issue is a screen reader issue, you should still get in the habit of testing your site with one. Not an emulator, simulator, or some other proxy solution.

If you find yourself struggling to operate a complicated interactive component using basic screen reader commands, it’s probably a sign that the component needs to be simplified. Chances are that the simplification will help non-assistive technology users as well. Good design benefits everyone!

The same goes for navigation. If it’s difficult to move around the website or web app, it’s probably a sign that you need to update your heading structure and landmark roles. Both of these features are used by assistive technology to quickly and efficiently navigate.


Two code examples for a sidebar. One uses a div element, while the others uses an aside element. Both have the class of sidebar applied to them, with a subheading of Recent Posts.


Both of these are sidebars, but only one of them is semantically described as such. A computer doesn’t know what a sidebar is, so it’s up to you to tell it.

Another good thing to review is the text content used to describe your links. Hopping from link to link is another common assistive technology navigation technique; some screen readers can even generate a list of all link content on the page:

“Think before you link! Your "helpful" click here links look like this to a screen reader user. ALT = JAWS links list”

Tweet by Neil Milliken

Neil Milliken

When navigating using an ordered list devoid of the surrounding non-link content, avoiding ambiguous terms like “click here” or “more info” can go a long way to ensuring a person can understand the overall meaning of the page. As a bonus, it’ll help alleviate cognitive concerns for everyone, as you are more accurately explaining what a user should expect after activating a link.

How To Test

Each screen reader has a different approach to how it announces content. This is intentional. It’s a balancing act between the product’s features, the operating system it is installed on, the form factor it is available in, and the types of input it can receive.

The Browser Wars taught us the folly of developing for only one browser. Similarly, we should not cater to a single screen reader. It is important to note that many people rely exclusively on a specific screen reader and browser combination — by circumstance, preference, or necessity’making this all the more important. However, there is a caveat: each screen reader works better when used with a specific browser, typically the one that allows it access to the greatest amount of accessibility API information.

All of these screen readers can be used for free, provided you have the hardware. You can also virtualize that hardware, either for free or on the cheap.

Automate

Automated accessibility tests should be your first line of defense. They will help you catch a great deal of nitpicky, easily-preventable errors before they get committed. Repeated errors may also signal problems in template logic, where one upstream tweak can fix multiple pages. Identifying and resolving these issues allows you to spend your valuable manual testing time much more wisely.

It may also be helpful to log accessibility issues in a place where people can collaborate, such as Google Sheets. Quantifying the frequency and severity of errors can lead to good things like updated documentation, opportunities for lunch and learn education, and other healthy changes to organizational workflow.

Much like manual testing with a variety of screen readers, it is recommended that you use a combination of automated tools to prevent gaps.

Windows

The two most popular screen readers on Windows are JAWS and NVDA.

JAWS

JAWS (Job Access With Speech) is the most popular and feature-rich screen reader on the market. It works best with Firefox and Chrome, with concessions for supporting Internet Explorer. Although it is pay software, it can be operated in full in demo mode for 40 minutes at a time (this should be more than sufficient to perform basic testing).

NVDA

NVDA (NonVisual Desktop Access) is free, although a donation is strongly encouraged. It is a feature-rich alternative to JAWS. It works best with Firefox.

Narrator

Windows comes bundled with a built-in screen reader called Narrator. It works well with Edge, but has difficulty interfacing with other browsers.

Apple

macOS

VoiceOver is a powerful screen reader that comes bundled with macOS. Use it in conjunction with Safari, first making sure that full keyboard access is enabled.

iOS

VoiceOver is also included in iOS, and is the most popular mobile screen reader. Much like its desktop counterpart, it works best with Safari. An interesting note here is that according to the 2017 WebAIM screen reader survey, a not-insignificant amount of respondents augment their phone with external hardware keyboards.

Android

Google recently folded TalkBack, their mobile screen reader, into a larger collection of accessibility services called the Android Accessibility Suite. It works best with Mobile Chrome. While many Android apps are notoriously inaccessible, it is still worth testing on this platform. Android’s growing presence in emerging markets, as well as increasing internet use amongst elderly and lower-income demographics, should give pause for consideration.

Popular screen readers
Screen Reader Platform Preferred Browser(s) Manual Launch Quit
JAWS Windows Chrome, Firefox JAWS 2018 Documentation Launch JAWS as you would any other Windows application Insert + F4
NVDA Windows Firefox NVDA 2018.2.1 User Guide Ctrl + Alt + N Insert + Q
Narrator Windows Edge Get started with Narrator Windows key + Control + Enter Windows key + Control + Enter
VoiceOver macOS Safari VoiceOver Getting Started Guide Command + F5 or tap the Touch ID button 3 times Command + F5 or tap the Touch ID button 3 times
Mobile VoiceOver iOS Mobile Safari VoiceOver overview – iPhone User Guide Tell Siri to, “Turn on VoiceOver.” or activate in Settings Tell Siri to, “Turn off VoiceOver.” or deactivate in Settings
Android Accessibility Suite Android Mobile Chrome Get started on Android with TalkBack Press both volume keys for 3 seconds Press both volume keys for 3 seconds

Call The Professionals

If you do not require the use of assistive technology on a frequent basis then you do not fully understand how the people who do interact with the web.

Much like traditional user testing, being too close to the thing you created may cloud your judgment. Empathy exercises are a good way to become aware of the problem space, but you should not use yourself as a litmus test for whether the entire experience is truly accessible. You are not the expert.

If your product serves a huge population of users, if its core base of users trends towards having a higher probability of disability conditions (specialized product, elderly populations, foreign language speakers, etc.), and/or if it is required to be compliant by law, I would strongly encourage allocating a portion of your budget for testing by people with disabilities.

“At what point does your organisation stop supporting a browser in terms of % usage? 18% of the global pop. have an #Accessibility requirement, 2% people have a colour vision deficient. But you consider 2% IE usage support more important? Support everyone be inclusive.”

Mark Wilcock

This isn’t to say you should completely delegate the responsibility to these testers. Much as how automated accessibility testing can detect smaller issues to remove, a first round of basic manual testing helps professional testers focus their efforts on the complicated interactions you need an expert’s opinion on. In addition to optimizing the value of their time, it helps to get you more comfortable triaging. It is also a professional courtesy, plain and simple.

There are a few companies that perform manual testing by people with disabilities:

Designed Experiences

We also need to acknowledge the other large barrier to accessible sites that can’t be automated away: poor user experience.

User experience can make or break a product. Your code can compile perfectly, your time to first paint can be lightning quick, and your Webpack setup can be beyond reproach. All this is irrelevant if the end result is unusable. User experience encompasses all users, including those who navigate with the aid of assistive technology.

If a person cannot operate your website or web app, they’ll abandon it and not think twice. If they are forced to use your site to get a service unavailable by other means, there’s a growing precedent for taking legal action (and rightly so).

As a discipline, user experience can be roughly divided into two parts: how something looks and how it behaves They’re intrinsically interlinked concepts — work on either may affect both. While accessible design is a topic unto itself, there are some big-picture things we can keep in mind when approaching accessible user experiences from a testing perspective:

How It Looks

The WCAG does a great job covering a lot of the basics of good design. Color contrast, font size, user-facing state: a lot of these things can be targeted by automation. What you should pay attention to is all the atomic, difficult to quantify bits that compound to create your designs. Things like the words you choose, the fonts you use to display them, the spacing between things, affordances for interaction, the way you handle your breakpoints, etc.

“A good font should tell you:
the difference between m and rn
the difference between I and l
the difference between O and 0.”

mallory, alice & bob

It’s one of those “an ounce of prevention is worth a pound of cure” situations. Smart, accessible defaults can save countless time and money down the line. Lean and mean startups all the way up to multinational conglomerates value efficient use of resources, and this is one of those places where you can really capitalize on that. Put your basic design patterns — say collected in something like a mood board or living style guide — in front of people early and often to see if your designed intent is clear.

How It Behaves

An enticing color palette and collection of thoughtfully-curated stock photography only go so far. Eventually, you’re going to have to synthesize all your design decisions to create something that addresses a need.

Behavior can be as small as a microinteraction, or as large as finding a product and purchasing it. What’s important here is to make sure that all the barriers to a person trying to accomplish the task at hand are removed.

If you’re using personas, don’t create a separate persona for a user with a disability. Instead, blend accessibility considerations into your existing ones. As a persona is an abstracted representation of the types of users you want to cater to, you want to make sure the kinds of conditions they may be experiencing are included. Disability conditions aren’t limited to just physical impairments, either. Things like a metered data plan, non-native language, or anxiety are all worth integrating.

“When looking at your site's analytics, remember that if you don't see many users on lower end phones or from more remote areas, it's not because they aren't a target for your product or service. It is because your mobile experience sucks.
As a developer, it's your job to fix it.”

Estelle Weyl

User testing, ideally simulating conditions as close to what a person would be doing in the real world (including their individual device preferences and presence of assistive technology), is also key. Verifying that people are actually able to make the logical leaps necessary to operate your interface addresses a lot of cognitive concerns, a difficult-to-quantify yet vital thing to accommodate.

We Shape Our Tools, Our Tools Shape Us

Our tool use corresponds to the kind of work we do: Carpenters drive nails with hammers, chefs cook using skillets, surgeons cut with scalpels. It’s a self-reinforcing phenomenon, and it tends to lead to over-categorization.

Sometimes this over-categorization gets in the way of us remembering to consider the real world. A surgeon might have a carpentry hobby; a chef might be a retired veterinarian. It’s important to understand that accessibility is everyone’s responsibility, and there are many paths to making our websites and web apps the best they can be for everyone. To paraphrase Mikey Ilagan, accessibility is a holistic practice, essential to some but useful to all.

Used with discretion, ARIA is a very good tool to have at our disposal. We shouldn’t shy away from using it, provided we understand the how and why behind why they work.

The same goes for automated accessibility tests, as well as GPS apps. They’re great tools to have, just get to know the terrain a little bit first.

Resources

Automated Accessibility Tools

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The Importance Of Manual Accessibility Testing

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How De Nieuwe Zaak Improved Productivity Using The VWO API

About De Nieuwe Zaak

De Nieuwe Zaak is a leading full-service digital agency based in Zwolle, Netherlands. With a team of over 90 experts, they provide innovative, high-quality digital commerce solutions for retailers, wholesalers, and brands alike.

They have been using VWO since 2012 to conduct A/B tests and optimize websites for many of their clients. Being such an extensive VWO user, they are constantly investigating how they can make use of the platform to make their processes more efficient and produce faster results.

De Nieuwe Zaak recently started using the VWO Application Programming Interface (API), which has drastically improved the productivity of their development teams with regard to building A/B test campaigns by using VWO. They recently published a blog post sharing their experience using VWO and the API; you can read it here.

Challenges Before Using VWO API

De Nieuwe Zaak has more than 12 years of experience in implementing and creating web applications. In these years, they have standardized their development process.

For them, setting up A/B tests is a collaboration between CRO & UX consultants and developers. The CRO & UX consultant analyzes the user research data and comes up with a hypothesis for an A/B test, and developers write the code for it.

Front-end developers work in their own Integrated Development Environment (IDE), such as Visual Studio, Sublime, or Webstorm, as these editors provide excellent support for writing code in HTML, SCSS, and JavaScript. After a piece of code is complete, it is stored in a version management system such as GIT and Bitbucket so that it is never lost.

Before the front-end developers at De Nieuwe Zaak started using the VWO API, they used to write the code for the test variations on the VWO code editor. However, they wanted to be able to write code in the IDE familiar to them for improved efficiency.

How VWO API Helped Improve Productivity

Developers at De Nieuwe Zaak used the VWO API to visualize tests in dashboards, analyze test results, and implement code changes in their campaigns. Here is how the process worked:

For any API to work, 2 applications are required. With one being VWO, developers at De Nieuwe Zaak wrote a small NodeJS application that now runs on their computers with the help of extensive documentation provided by VWO.

The NodeJS application communicates with VWO by using an automated task runner called GruntJS and an asynchronous request initiated by the browser, also known as an Ajax call.

With the first version of the VWO API, front-end developers at De Nieuwe Zaak were able to retrieve the JavaScript and CSS code pieces from their version management system, and then push the changes to VWO. Further, they could accommodate using SCSS instead of CSS, which is easier to manage and write code in. Below is a schematic representation of the process:

Summary of Benefits

De Nieuwe Zaak is one of the first VWO customers worldwide that started using the VWO API. In addition to improving their efficiency and reducing the overall time spent from scratch till the end for implementing a test, the development team at De Nieuwe Zaak has been able to:

  • Improve code quality by using SCSS, instead of plain CSS.
  • Write code in an environment familiar to them.
  • Ensure safety of their code by using version management.
  • Create and extend the API link to further accommodate their use cases.
  • Follow their existing processes and frameworks to develop websites.

The VWO API is very extensive and is very well documented. At De Nieuwe Zaak, we use the API for visualizing reports in dashboards and implementing test. Particularly, the process of implementing tests with the API made the implementation more sustainable.

– Pascal Alferink, Developer at De Nieuwe Zaak

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How De Nieuwe Zaak Improved Productivity Using The VWO API

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Live Chat vs Chat Bots: Optimizing Your Customer Service for a Delightful Experience

live-chat

Live chat and chatbots are gaining popularity. And there is a good reason for that: modern businesses continue to look for innovative way to improve their customers’ experience while they search for answers to their queries in real time. While some have opted for live chat, others prefer a chatbot. But the intent remains the same: improving customer service. Which of these options is better suited for your business? Both have their distinct pros and cons. Although a human-powered, live support software is a common element on most websites these days, there has a been a lot of noise about…

The post Live Chat vs Chat Bots: Optimizing Your Customer Service for a Delightful Experience appeared first on The Daily Egg.

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Live Chat vs Chat Bots: Optimizing Your Customer Service for a Delightful Experience

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Results From Our Latest A/B Test: Here’s The New VWO Logo!

Over the past 8 years, we’ve made some key (and some minor) changes to the look and feel of our brand. Around this time last year, we revamped our website for the launch of VWO Conversion Optimization Platform™.

As an organization that thrives on a culture of experimentation, we are always looking into data to discover insights for optimization. By turning our opinions into hypotheses, we test changes for almost everything which could have a significant impact on the business, and then derive the next logical step. Based on this simple framework, we recently made a minor change to the VWO logo. Before we delve further into the hypothesis behind this change, look at the logo in its full glory:

The Hypothesis: Making The Letters V, W, and O Prominent Will Improve Readability

In the beginning, our product was called Visual Website Optimizer. However, over the years, people (including us) fondly started abbreviating it to VWO. This is what the VWO logo looked like during this gradual change:

More recently, we dropped the accompanying text “Visual Website Optimizer” completely, and also started referring to our product as just “VWO.”

With this change, we realized that it would be hard for someone unfamiliar with our brand to read or understand our logo. We hypothesized that if the letters “V,” “W,” and “O” were made distinguishable, the brand name VWO would stand out more clearly.

The Test: Conducting an A/B/C Test to Choose a Winner

After the hypothesis was finalized, our design team created a new variation of the logo, per the new specification. Next, we decided to test the hypothesis by conducting extensive user testing through 5-second tests on UsabilityHub.

Five-second tests are a method of usability testing, where the participants are shown a visual for only 5 seconds, and then asked questions corresponding to it.

For our tests, we selected a sample of participants from across the globe, with varying demographics, location, and other attributes. They were showed the 3 variations of the logo—the existing one, the proposed one, and the one with VWO written as well-spaced plain text. Next, we asked the participants the question “What do you read?” to which they had to type in a response.

For the proposed logo, we got 90% of them answering “VWO”, as opposed to only 66% for the existing one. For the variation with VWO written as well-spaced text, the response was around 96%.

The Result: Reinforced Belief in the Potential of Testing

As an obvious next step, we decided to make this minor update to our logo which can now be seen to be live across all our digital properties. We’re proud of the fact that the basic tenets of experimentation continue to give direction to our efforts.

If it wasn’t for validating our initial, seemingly insignificant hypothesis, VWO wouldn’t have got a brand new identity. We strive to uphold this culture in our organization for the years to come.

What do you think of our new logo? Feel free to share your thoughts in the comments below.

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Results From Our Latest A/B Test: Here’s The New VWO Logo!

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Customers, Come Back! Learn How to Use Customer Retention to Your Advantage

customer-retention-introduction

Your best customers don’t just buy one product or use your service once. They come back again and again for more. Customer retention increases your customers’ lifetime value and boosts your revenue. It also helps you build amazing relationships with your customers. You aren’t just another website or store. They trust you with their money because you give them value in exchange. What does customer retention mean? And how can you achieve customer retention through relationship-building strategies? Let’s explore these concepts in depth and look at a few examples that you can apply to your own business. What is Customer…

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Customers, Come Back! Learn How to Use Customer Retention to Your Advantage

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What is Customer Retention, Importance, Examples & Techniques

customer-retention-introduction

Your best customers don’t just buy one product or use your service once. They come back again and again for more. Customer retention increases your customers’ lifetime value and boosts your revenue. It also helps you build amazing relationships with your customers. You aren’t just another website or store. They trust you with their money because you give them value in exchange. What what does customer retention mean? And how can you achieve customer retention through relationship-building strategies? Let’s explore these concepts in depth and look at a few examples that you can apply to your own business. What is…

The post What is Customer Retention, Importance, Examples & Techniques appeared first on The Daily Egg.

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What is Customer Retention, Importance, Examples & Techniques

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Suffering From Analysis Paralysis? You Should See An Optimization Specialist

crazy egg analysis tips

Have you ever faced down a giant table or spreadsheet of data and thought, “I have no idea what to do with this”? As marketers we’ve all probably had those deer-in-the-headlights moments once or twice, where we’ve floundered to figure out what the hell we’re looking at. Crazy Egg was built on the premise of simplicity and ease of use, for those that I fondly like to call “Google Analytics-averse” – but there’s always room for improvement when it comes to helping folks switch from analysis to action mode. Whether you’re a UX designer, small business owner, SEO expert or…

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Suffering From Analysis Paralysis? You Should See An Optimization Specialist

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Getting Started With Machine Learning




Getting Started With Machine Learning

Alvin Wan



The goal of machine learning is to find patterns in data and use those patterns to make predictions. It can also give us a framework to discuss machine learning problems and solutions — as you’ll see in this article.

First, we will start with definitions and applications for machine learning. Then, we will discuss abstractions in machine learning and use that to frame our discussion: data, models, optimization models, and optimization algorithms. Later on in the article, we will discuss fundamental topics that underlie all machine learning methods and conclude with practical guidance for getting started with using machine learning. By the end, you should have an understanding of how to advance your practice and study of machine learning.

Let’s begin.

So, What Exactly Is Machine Learning?

Machine learning is generically a set of techniques to find patterns in data. Applications range from self-driving cars to personal AI assistants, from translating between French and Taiwanese to translating between voice and text. There are a few common applications of machine learning that already or could potentially permeate your day-to-day.

  1. Detecting anomalies
    Recognize spikes in website traffic or highlight abnormal bank activity.
  2. Recommend similar content
    Find products you may be looking for or even Smashing Magazine articles that are relevant.
  3. Predict the future
    Plan the path of neighboring vehicles or identify and extrapolate market trends for stocks.

The above are few of many applications of machine learning, but most applications tie back to learning the underlying distribution of data. A distribution specifies events and probability of each event. For example:

  • With 50% probability, you buy an item $5 or less.
  • With 25% probability, you buy an item $5-$10.
  • With 24% probability, you buy an item $10-100.
  • With 1% probability, you buy an item > $100.

Using this distribution, we can accomplish all of our tasks above:

  1. Detecting anomalies
    With a $100 purchase, we can confidently call this an anomaly.
  2. Recommend similar content
    A purchase of $3 means we should recommend more items $5 or less.
  3. Predict the future
    Without any prior information, we can predict that the next purchase will be $5 or less.

With a distribution of data, we can accomplish a myriad of tasks. In sum, one goal in machine learning is to learn this distribution.

Even more generically, our goal is to learn a specific function with particular inputs and outputs. We call this function our model. Our input is denoted x. Say our model, which accepts input x, is

f(x) = ax

Here, a is a parameter of our model. Each parameter corresponds to a different instance of our model. In other words, the model where a=2 is different from the model where a=3. In machine learning, our goal is to learn this parameter, changing it until we do “well.” How do we determine which values of a do “well”?

We need to define a way to evaluate our model, for each parameter a. To start, the output of f(x) is our prediction. We will refer to y as our label, meaning the true and desired output. With our predictions and our labels, we can define a loss function. One such loss function is simply the difference between our prediction and our label, |f(x) - y|. Using this loss function, we can then evaluate different parameters for our model. Picking the best parameter for our model is known as training. If we have a few possible parameters, we can simply try each parameter and pick the one with the smallest loss!

However, most problems are not as simple. What happens if there are an infinite number of different parameters? Let’s say all decimal values between 0 and 1? Between 0 and infinity? This brings us to our next topic: abstractions in machine learning. We will discuss different facets of machine learning, to compartmentalize your knowledge into data, models, objectives, and methods of solving objectives. Beyond learning the right parameter, there are plenty of other challenges: how do we break down a problem as complex as controlling a robot? How do we control a self-driving car? What does it mean to train a model that identifies faces? The section below will help you organize answers to these questions.

Abstractions

There are countless topics in machine learning — at various levels of specificity. To better understand where each piece fits in the larger picture, consider the following abstractions for machine learning. These abstractions compartmentalize our discussion of machine learning topics, and knowing them will make it easier for you to frame topics. The following classifications are taken from Professor Jonathan Shewchuck at UC Berkeley:

  1. Application and Data
    Consider the possible inputs and the desired output for the problem.
    Questions: What is your goal? How is your data structured? Are there labels? Is it reasonable for us to extract output from the provided inputs?

    Example: The goal is to classify pictures of handwritten digits. The input is an image of a handwritten number. The output is a number.

  2. Model
    Determine the class of functions under consideration.
    Questions: Are linear functions sufficient? Quadratic functions? Polynomials? What types of patterns are we interested in? Are neural networks appropriate? Logistic regression?

    Example: Linear regression

  3. Optimization Problem
    Formulate a concrete objective in mathematics.
    Questions: How do we define loss? How do we define success? Should we apply additionally penalties to bias our algorithm? Are there imbalances in the data our objective needs to consider?

    Example: Find `x` that minimizes |Ax-b|^2

  4. Optimization Algorithm
    Determine how you will solve the optimization problem.
    Questions: Can we compute a solution by hand? Do we need an iterative algorithm? Can we convert this problem to an equivalent but easier-to-solve objective, and solve that one?

    Example: Take derivative of the function. Set it to zero. Solve for our optimal parameter.

Abstraction 1: Data

In practice, collecting, managing, and packaging data is 90% of the battle. The data contains samples in which each sample is a specific realization of our input. For example, our input may generically be images of dogs. The first sample is specifically a picture of Maxie, my Bernese Mountain dog-chow chow mix at home. The second sample is specifically a picture of Charlie, a young corgi.

While training your model, it is important to handle your data properly. This means separating our data accordingly and not peeking prematurely at any set of data. In general, our data is split into three portions:

  1. Training set
    This is the dataset you train your model on. The model may see this set hundreds of times.
  2. Validation set
    This is the dataset you evaluate your model on, to assess accuracy and tune your model or method accordingly.
  3. Test set
    This is the dataset you evaluate on to assess accuracy, once at the very end. Running on the test set prematurely could mean your model overfits to the test set as well, so run only once. We will discuss the notion of “overfitting” in more detail below.

Abstraction 2: Models

Machine learning methods are split into the following two:

Supervised Learning

In supervised learning, our algorithm has access to labeled data. Still, we explore the following two classes of problems:

  • Classification
    Determine which of k classes C_1, C_2, ... C_k to which each sample belongs, e.g. “Which breed of dog is this?” The dog could be one of "corgi", "bernese mountain dog", "chow chow"...
  • Regression
    Determine a real-valued output (which are often probabilities), e.g. “What is the probability this patient has neuroblastoma (eye cancer)?”
Unsupervised Learning

In unsupervised learning, our algorithm does not have access to labels, and we explore the following classes of problems:

  • Clustering
    Cluster samples into k clusters. We do not have a label for the resulting clusters. “Which DNA sequences are most similar?”
  • Dimensionality reduction
    Reduce the number of “unique” (linearly independent) features we consider. “What are common features of faces?”

Abstraction 3: Optimization Objective

Before discussing optimization objectives and algorithms, we’ll need an example to discuss. Least squares are the canonical example. We will restrict our attention to a specific form of least squares: Let us return to our grade-school problem of fitting a line to some points.

Let’s recall the equation of a line:

y = m * x + b

Assume we have such a line. This is the true underlying model.


 true model


True model. The line that generates our data. (Large preview)

Now, sample points from this line.


true data


True data. Data that is sampled from the true model. (Large preview)

For each point, jiggle it a little bit. In other words, add noise, which is random perturbations. This noise is due to real-world processes.


noise


Noise. Real-world perturbations that affect our data. This may be due to imprecision in measurements, lossy compression, and so on. (Large preview)

This gives us our observed data. We will call these points (x_1, y_1), (x_2, y_2), (x_3, y_3).... This is the training data we are given to train a model on. We do not have access to the underlying line that generated this data (the original green line).


observations


Observations. Our true data with noise and ultimately what we will use to train a model. (Large preview)

Say we have an estimate for the parameters of a line. In this case, the parameters are m and b. This gives us a predicted line, drawn in blue below.


proposed model


Proposed model. The result of training a model on our observations. (Large preview)

We wish to evaluate our blue line, to see how accurate it is. To start, we use m and b to estimate y. We compute a set of ŷ values.

ŷ_i = m * x_i + b

The error for a single predicted ŷ_i and true y_i is simply

(ŷ_i−y_i)^2

Our total error is then the sum of squared differences, across all samples. This yields our loss.

∑(ŷ_i−y_i)^2

Presented visually, this is the vertical distance between our observed points and our predicted line.


observed error


Observed error. The distance between our observed data and our proposed model. (Large preview)

Plugging in ŷ_i from above, we then have the total error in terms of m and b.

∑(m * x_i + b − y_i)^2

Finally, we want to minimize this quantity. This yields our objective function, abstraction 3 from our list of abstractions above.

min_m, b ∑(m * x_i + b−y_i)^2

The above states in mathematics that the goal is to minimize the loss by changing values of m and b. The purpose of this section was to motivate fitting a line of best of fit, a special case of least squares. Additionally, we showed examined the least squares objective. Next, we need to solve this objective.

Abstraction 4: Optimization Algorithm

How do we minimize this? We take the derivative with respect to m`, set to 0 and solve. After solving, we obtain the analytical solution. Solving for an analytical solution was our optimization algorithm, the fourth and final abstraction in our list of abstractions.

Note: The important portion of this section is to inform you that least squares have a closed form solution, meaning that the optimal solution for our problem can be computed, explicitly. To understand why this is significant, we need to examine a problem without a closed-form solution. For example, we could never solve x=logx for a standard base-10 logarithm. Try graphing these two lines, and we see that they never intersect. In which case, we have no closed-form solution. On the other hand, ordinary least squares have a closed-form — which is good news. For any problem reduced to least squares, we can then compute the optimal solution, given our data and assumptions.

Fundamental Topics

Before studying more methods, it is necessary to understand the undercurrents of machine learning. These will govern the initial study of machine learning:

Bias-Variance Tradeoffs

One of machine learning’s most dreaded evils is overfitting in which a model is too closely tailored to the training data. In the limit, the most overfit model will memorize the data. This might mean that if one does well on exam A, one repeats every detail for exam B — down to the duration of an inter-exam restroom trip and whether or not one used the urinal.

A related but less common evil is underfitting, where the model is not sufficiently expressive to capture important information in the data. This could mean that one looks only at homework scores to predict exam scores, ignoring the effects of reading notes, completing practice exams, and more. Our goal is to build a model that generalizes to new examples while making the appropriate distinctions.

Given these two evils, there are a variety of approaches to fighting both. One is modifying your optimization objective to include a term that penalizes model complexity. Another is tuning hyperparameters that govern either your objective or your algorithm, which may correspond to notions such as “training speed” or “momentum.” The bias-variance tradeoff gives us a precise way of defining and handling both overfitting and underfitting.

Maximum Likelihood Estimation (MLE) + Maximum A Posteriori (MAP)

Say we have ice cream flavors A, B, and C. We observe different recipes. Our goal is to predict which flavor each recipe produces.

One way to predict flavors based on recipes is to first estimate the following probability:

P(flavor|recipe)

Given this probability and a new recipe, how can we predict the flavor? Given a recipe, simply consider the probability of each of the flavors A, B, C.

P(flavor=A|recipe) = 0.4
P(flavor=B|recipe) = 0.5
P(flavor=C|recipe) = 0.1

Then, pick the flavor that has the highest probability. Above, flavor B has the highest probability, given our recipe. Thus, we predict flavor B. Restating the above rule in mathematics, we have:

argmax_flavor P(flavor|recipe)  # argmax means take the flavor that corresponds to the max value

However, the only information at our disposal is the reverse: the probability of some recipe given the flavor.

P(recipe|flavor)

For Maximum Likelihood Estimates, we make assumptions and find that the two values are proportional.

P(recipe|flavor) ~ P(flavor|recipe)

Since we’re only interested in the class with maximum probability P(flavor|recipe), we can simply find the class with maximum probability, for a proportional value P(recipe|flavor).

argmax_flavor P(recipe|flavor)

MLE offers the above objective as one way to predict, using the probability of data given the labels.

However, allow me to convince you that it’s reasonable to assume we have (x|y). We can estimate this from observed, real-world data. For example, say we wish to estimate the number of marbles each student in your class carries, based on the number of rubber ducks the student carries.

Each student’s number of rubber ducks is the data x, and the number of marbles she or he has is y. We will use this sample data below.

| x | y |
|---|---|
| 1 | 2 |
| 1 | 1 |
| 1 | 2 |
| 2 | 1 |
| 2 | 2 |
| 1 | 2 |

For every y, we can compute the number of x, given us P(x|y). For the first one, P(x=1|y=1), consider all of the rows where y=1. There are 2, and only one of them has x=1. Therefore, P(x=1|y=1) = 12. We can repeat this for all values of x and y.

P(x=1|y=1) = 1/2
P(x=2|y=1) = 1/2
P(x=1|y=2) = 3/4
P(x=2|y=2) = 1/4

Featurizations, Regularization

Least squares draw lines of best fit for us. Note that least squares can fit the model anytime the model is linear in its inputs x and outputs y.

Say m=1. We have the following equation:

y = x + b

However, what if we had data that doesn’t generally follow a line? Specifically, consider a set of data sampled along a circle. Recall that the equation for a circle is:

x^2 + y^2 = r^2

Can least squares fit this well? As it stands, no. The model is not linear in its inputs x and outputs y. Instead, the model above is quadratic in x and y. However, it turns out that we can use still use least squares, just with a modification. To accomplish this, we featurize our samples.

Consider the following: what if the input to our model was x_ = x^2 and y_ = y^2? Then, our model is trying to learn the following model.

x_ + y_ = r^2

Is this linear in the model’s input x_ and output y_? Yes. Note the subtlety. The current model is still quadratic in x,y but it is linear in x_,y_. This means that least squares can fit the data if we square x^2 and y^2 before training least squares.

More generally, we can take any non-linear featurization to apply least squares to labels that are non-linear in the features. This is a fairly powerful tool, known as featurization.

However, featurizations lead to more complex models. Regularization allows us to penalize model complexity, ensuring that we do not overfit the training data.

Conclusion

In this article, you’ve touched on major topics in the fundamentals of machine learning. Using the abstractions above, you now have a framework to discuss machine learning problems and solutions. Using the fundamental topics above, you now also have quintessential concepts to learn more about, giving you the necessary tools to evaluate risk and other concerns in a machine learning application.

Further Reading

We will continue to explore these topics in depth, both the undercurrents of machine learning and specific methods. In the interim, here are resources to further your study and exploration of machine learning:

Smashing Editorial
(ra, il)


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Getting Started With Machine Learning