A Guide to the "Essential" survey

There was a lot of confusion on the call today regarding the survey for Breaking Out the Multiple Changes to "Essential":
https://www.w3.org/2002/09/wbs/35422/essential_breakout/

Comments from the survey and chatter today reflect some misunderstanding about why such changes are needed, so my goal is to explain why and show my rationale on each change.  Hopefully this helps some folks take the survey or update their answers.

## Why so many changes?
Michael Cooper filed the original issue #372<https://github.com/w3c/wcag21/issues/372>, and I took a stab at analyzing all places where "essential" is used.  Let's start by examining the glossary definition:

"if removed, would fundamentally change the information or functionality of the content, ..." - This part is not such a problem as it sort of directly takes a dictionary definition of essential applied to web content.  This is the part I think most of us think of right away, but then the definition goes on to say...

"... and information and functionality cannot be achieved in another way that would conform" - This clause is the primary problem; it directly states that the "essential" adjective is describing content that does not conform, which means we can only use "essential" to describe an exception to a criterion.

So this led me to pull request #398<https://github.com/w3c/wcag21/pull/398>.  Some corrections were as simple as linking to the definition, whereas others need to alter their language to not say "essential" since it means something special to WCAG.  For the latter, I proposed what I thought was the least obtrusive and honored the actual intent.

## Correct Uses
Let's start with the SC that were using essential correctly in an exception, but not linking to it:

*       Graphics Contrast (exception only) [not mentioned in survey question 8]

*       Pointer Gestures [question 9]

*       Concurrent Input Mechanisms [question 5]

*       Device Sensors [question 7]

*       Accidental Activation [question 2]
These were corrected by simply adding the link to make the usage clear - SC language is identical otherwise.

Next, let's look at Animation from Interactions [question 4].  This criterion is actually using the term correctly as an exception to restrict applicability to "non-essential animations", but it's an awkward read. This draft just moves the clause to a clear exception at the end, saying "unless the animation is essential."

## Incorrect Uses
And now the harder ones that are using it incorrectly and we must change...

### Graphics Contrast [question 8]
This criterion restricts applicability to "graphical objects that are essential for understanding the content or functionality".  The draft fix here simply replaces "essential" with "necessary" as an appropriate synonym.

### User Interface Component Contrast [question 10]
This criterion restricts its applicability to "essential visual identifiers".  Given that the notes and Understanding are going into detail about what that means and it is not tied to the definition, this draft just strikes the word "essential" from this phrase everywhere.  My logic is that saying "essential" is mostly redundant with the word "identifier", i.e. if something visual is identifying the type of component or its state, then it is always essential.

### Adapting Text [question 3]
The criterion refers to "no loss of essential content or functionality".  The word seems to have been introduced by @awkawk in a [comment way back in March](https://github.com/w3c/wcag21/issues/78#issuecomment-289792275), but I could not find any rationale for its inclusion in the language (i.e. an example of content loss that would be acceptable).  Given this, and the fact that both Resize Text and Zoom Content refer to "loss of content or functionality" without using essential, this draft simply removes the word from this SC.

### Content on Hover or Focus [question 6]
This criterion says that the additional content should not "obscure any essential content within the trigger".  The use here is meant to say that decorative content is okay to obscure, so this draft rewords the sentence to link to the definition of "pure decoration" instead.

### Accessible Authentication [question 1]
This criterion restricts the applicability to "essential" steps, but it appears to me that this is really meant as a synonym for "required" steps.  The 2nd use in the bullet I believe is unnecessary to the SC.  So, this draft simply replaces "essential" with "required" to correct the former misuse and delete the latter use.

### No Timing  (not addressed via this request)
Yes, an existing AAA criterion is using "essential" incorrectly.  However, it is clear to me from the SC that this is simply meant to be a synonym for "required", and the Understanding content even just says required and gives no rationale for using "essential".  I recommend we replace "essential" with "required" as WCAG 2.0 errata and merge into 2.1.

Steve Repsher
Twitter<https://twitter.com/steverep> | LinkedIn<https://www.linkedin.com/in/steverepsherjr/> | GitHub<https://github.com/steverep>

Received on Wednesday, 4 October 2017 04:00:13 UTC