Re: Guideline 3.2 question - functional and interactive components

I think I understand your frustration behind your question.

The term "component" is used 36 times in WCAG 2.0. 

For example, the term "user interface component" is used in 
Principle 1: Perceivable - Information and user interface components must 
be presentable to users in ways they can perceive.

sometimes there is only the term "component" in the text without any 
qualifying adjectives or additional terms, such as in 
1.3.3 Sensory Characteristics: Instructions provided for understanding and 
operating content do not rely solely on sensory characteristics of 
components such as shape, size, visual location, orientation, or sound. 
(Level A) 

there are also more 'compound' uses of the term, such as "inactive user 
interface component", as used in 
1.4.3 Contrast (Minimum): The visual presentation of text and images of 
text has a contrast ratio of at least 4.5:1, except for the following: 
(Level AA)
Incidental: Text or images of text that are part of an inactive user 
interface component, that are  . . . 

and your question seems to suggest there are different kinds of 
"components" when the Understanding WCAG 3.2 Predictable Guideline 
explains that 
"The intent of this Guideline is to help users with disabilities by 
presenting content in a predictable order from Web page to Web page and by 
making the behavior of functional and interactive components predictable." 


But immediately inside this 3.2 guideline, in the success criteria 
suggests the term "component" applies to any components, such as in 
        3.2.1 On Focus: When any component receives focus, it does not 
initiate a change of context. (Level A) 

while the next success criteria in this 3.2 guidelines, explicitly use the 
normative term, such as in
        3.2.2 On Input: Changing the setting of any user interface 
component does not automatically cause a change of context unless the user 
has been advised of the behavior before using the component. (Level A) 

and to further introduce complexity (or confusion or comprehensiveness), 
the next success criteria introduces a new normative defined term, 
"mechanism", perhaps a superset to component, such as 
        3.2.3 Consistent Navigation: Navigational mechanisms that are 
repeated on multiple Web pageswithin a set of Web pages occur in the same 
relative order each time they are repeated, unless a change is initiated 
by the user. (Level AA) 

to be comprehensive, the term "mechanism" is defined in a broader way 
including content, platform, user agents and assistive technologies in the 
WCAG Glossary, such as 
        mechanism
                process or technique for achieving a result
                Note 1: The mechanism may be explicitly provided in the 
content, or may be relied upon to be provided by either the platform or 
by user agents, including assistive technologies.
                Note 2: The mechanism needs to meet all success criteria 
for the conformance level claimed.

The term "user interface component" does also have a normative definition 
in the WCAG Glossary, such as 
        user interface component
        a part of the content that is perceived by users as a single 
control for a distinct function
Note 1: Multiple user interface components may be implemented as a single 
programmatic element. Components here is not tied to programming 
techniques, but rather to what the user         perceives as separate 
controls.
Note 2: User interface components include form elements and links as well 
as components generated by scripts.
Example: An applet has a "control" that can be used to move through 
content by line or page or random access. Since each of these would need 
to have a name and be settable independently, they would each be a "user 
interface component."

although "interactive" and "functional" are not defined, the term "
functionality" is defined, such as 
        functionality
processes and outcomes achievable through user action

So, in my opinion, the "user interface components" are "mechanisms" 
explicitly provided in content (not platforms, not user agents, nor 
assistive technologies) that include both functional and interactive 
components because there is little difference between the two, and it was 
the intent of the working group to be "inclusive and comprehensive" by 
using 'AND" of all user interface components, including both ones that 
function, such as a button the causes a change in the page, process or 
outcome, while an interactive component that causes a change in the user 
interface component itself, such as a checked or unchecked checkbox, not 
necessarily elsewhere on the page, process, or outcome.

my proposed edit: 
The intent of this Guideline is to help users with disabilities by 
presenting content in a predictable order from page to page and by making 
the behavior of functional and interactive user interface components 
predictable." 
and add additional glossary term or further explanation in the 
introductory paragraph in understanding 3.2 Predictable: 
Note 3: Functional user interface components (such as a button) may causes 
a change to the content, process, or outcome while an interactive user 
interface component may cause a change to the user interface component 
itself.  Example: A checkbox can by changed itself from checked to 
unchecked and back interactively by the user action.
 
I copied the "Understanding WCAG" editors so they can log this suggestions 
and update the text in the next errata and if/when the WCAG normative 
glossary will be updated.  My understanding is that WCAG 2.1 will NOT 
change anything normative in 2.0, only "add" to 2.0. So we could see an 
errata to the understanding WCAG document sooner.
___________
Regards,
Phill Jenkins
pjenkins@us.ibm.com
Senior Engineer & Accessibility Executive
IBM Research Accessibility
linkedin.com/in/philljenkins/




From:   Joseph Yang <joesaiyang@gmail.com>
To:     WAI IG <w3c-wai-ig@w3.org>
Date:   01/25/2018 02:05 PM
Subject:        Guideline 3.2 question



What is the difference between a functional component and an interactive 
component?