- From: Gregg Vanderheiden <gv@trace.wisc.edu>
- Date: Wed, 30 Nov 2005 17:19:12 -0600
- To: "'Tim Boland'" <frederick.boland@nist.gov>, <w3c-wai-gl@w3.org>
Good catch. This should say "violates neither the general nor the red..." If no objections I will bring up with the WG for a change. Gregg -- ------------------------------ Gregg C Vanderheiden Ph.D. Professor - Ind. Engr. & BioMed Engr. Director - Trace R & D Center University of Wisconsin-Madison -----Original Message----- From: w3c-wai-gl-request@w3.org [mailto:w3c-wai-gl-request@w3.org] On Behalf Of Tim Boland Sent: Wednesday, November 30, 2005 2:46 PM To: w3c-wai-gl@w3.org Subject: parsing issue with SC 2.3.2? SC 2.3.2 states: "Content does not violate general flash threshold or red flash threshold" How should this sentence be parsed? What rules of precedence should apply? Is the parsing "(Content does not violate general flash threshold) or (content does not violate red flash threshold)" or is the parsing "Content does not violate (both general flash threshold and red flash threshold)"? For the former parsing (using Boolean algebra approach?), if one of the clauses in parentheses is true, then the entire sentence is true (x OR y = 1 if x=1 or y=1 or both). For the latter parsing, the clause in parentheses constitutes an AND operation (condition) (meaning that satisfaction of both thresholds has to be met simultaneously?) (x AND y=1 if and only if both x=1 and y=1 at the same time), so the sentence is only true if content does not violate both clauses at the same time. Which parsing is meant by the WCAG WG for SC 2.3.2? This question may need to be answered for testability of this SC.. I investigated the SC2.3.2 Guide Document for this SC, which in the "intent" section seems to imply to me that the red flash threshold is a "special" threshold above and beyond the general flash threshold. If content satisfies the general flash threshold requirement, does it meet this SC (general flash threshold is defined in terms of a "sequence", and red flash threshold is defined in terms of a "transition")? Or does content need to meet both the general flash threshold and the red flash threshold simultaneously in order to meet this SC? What is the relationship (if any) between general flash threshold and red flash threshold? Are these "independent" guidelines for the broadcast industry, or does one build upon the other in some sense? Perhaps some clarification is needed (maybe in the Guide Document?), as a novice reader may find the parsing of the subject sentence confusing? Apologies if this question is already answered somewhere.. Thanks and best wishes Tim Boland NIST
Received on Wednesday, 30 November 2005 23:19:24 UTC