Re: Use and abuse of @summary

Hi Steve,

Steven Faulkner 2009-02-18 11.20:

> After last weeks html working group teleconference I undertook a small study
> myself: summary attribute usage data (
> I am not making any
> wild claims about this study, but do suggest that from this sample, for the
> large majority of cases where @summary was used, it was used on data tables
> in way that may be useful to the users its intended for.

Here are some comments about some of the tables you looked at:

[1] The "Vegetarian Journal 2006" page has 21 summaries which all 
appear to be identical with the table caption (which isn't a 
<caption> but a <TD> cell.) Thus Jaws seem to read same text 
twice. A stronger link between <caption> and @summary could 
probably have helped the author to not make these mistakes. (The 
author apparently knew about [the usefulness of] @summary, but not 
about [the usefulness of] <caption>.)

[2] The Wikipedia example in Philip Taylor's collection has a TOC 
<TABLE> with a @summary saying "Contents", which is ignored by 
Jaws. The Hn element (which also says "Contents") prevents the 
author from using <caption>. The problem here is, again, that 
<caption> isn't used. (And that table is used at all.)

[3] In the "2007 Federal Tax Rate Schedules" sample, each @summary 
first identify the table by repating the text in the preceding H3 
element, before explaining the table. If the headers had been 
inside a <caption>, then it had worked better for the screen 
reader users. So, again a problem related to <caption>. (The 
@summary text might have been useful for visual UA users as well.)

[4] For the "Frequently Asked Questions Related to the Poverty 
Guidelines and Poverty" table, yes they misuse @summary for 
telling that it is a layout table. However, they also use 
<caption> in the data table on the same page. A hint that getting 
attention to <caption> is the right thing.

[5] For the "NHLBI, Obesity Guidelines-Executive Summary-BMI 
Chart", they offers *a long* <caption> (276 chars) and a short 
@summary (45 chars). It appears as if Jaws here reads the summary 
first, before the caption. Probably because the summary is shorter 
than the caption? Heuristics at work. Well done.

Summary: All this hints that authors have problems with the 
relationship between <caption> and @summary. Sometimes I also 
think they have problems with the very <caption> element: Getting 
it to look right etc. Placing headers inside it or not.

Would it be a useful "cowpath" to permit H1-H6 elements inside 
<caption> so that <caption> could serve both as table title and 
document header? At leaste I think that this could provide for 
better captioning  in some cases. The New York Institute for 
Special Education, on their introduction pages about Jaws, 
allready recommend doing this: "... each table also has a caption 
that is a level two heading ..." [6]

> In conclusion: @summary is well supported by AT , its misuse at whatever
> level (though I would say claims are overstated) has little effect upon
> users.
> Therefore I suggest that it would be useful to talk to the screen reader
> users (its intended audience) that are on the W3C HTML working group and the
> W3C WAI groups and heed their advice on the utility of the @summary.

Based on looks at the source code of your collection and also the 
tests with Jaws, this is probably right. But there seems to very 
much room for improvement, in order to get authors to get it right 
and thuse serve users better.

I wish we could move on to discuss how to add table summaries and 
table captions correctly. Both table summaries and <caption> 
should be treated under the same subject: meta data of tables. I 
think is needed that one set up usecases, the same way that 
usecases for correctly used @alt have been set up. Whether 
@summary is included or not, the specification is lacking 
*anything* about how to use <caption>, except that it says that it 
represents a title.

leif halvard silli

Received on Thursday, 19 February 2009 02:57:06 UTC