Interpreting SC 3.3.2

SC 3.3.2 Labels or instructions are provided when content requires user input. (Level A) 
Then from Understanding doc:
"The intent of this Success Criterion is to help users avoid making mistakes when their input is required. ..." 
The description for G131 seems to extend the strict intent of SC 3.3.2 with
"The objective of this technique is to ensure that the label for any interactive component within Web content makes the component's purpose clear."
This is more in line with the description of SC 3.3.2 that says "Blind users need to know exactly what information should be entered into form fields and what the available choices are. Simple instructions visually connected to form controls can assist users with cognitive disabilities or those accessing a page using a screen magnifier".
 
Question
So does SC 3.3.2 imply labels or instructions are not needed when completion of some fields is optional and not mandatory for successful submission of the form?

I think the SC is ambiguously worded.
All fields in a form, well, require user input but not every field is mandatory or 'required' in that sense.  
First and last name may be mandatory but middle name may not be.
So does it mean only first and last name fields need to be labelled because input is required?
But unless the fields are identified clearly via a label / title or some such programmatically determinable method one may not be able to identify the purpose of input field for middle name if it is not labelled.

Then again, is a mere instruction at the start of a form with 3 fields that says:
"Enter first, middle and last names in the form below", sufficient?
It may also say"First and last names are mandatory"

Does it make a difference, if in addition to the  above instructional text, if there are text labels positioned above the fields but not programmatically associated with the fields?
This meets G131 + G184.  
Would it make a difference if the form had more than these 3 fields ... say a dozen fields and some were optional?

Sailesh Panchang

Received on Friday, 27 July 2012 15:13:14 UTC