heading elements (h#) in tables?

I'm wondering if heading elements can be used to help make sense of a
complex table.

 

In this video (http://www.cfit.ie/html5_video/Table2.wmv), Josh O Connor is
leading Stewart Lawler (both from the NCBI) through a test of this table,
which uses an id/headers design:
http://www.wisc.edu/about/facts/budget.php#budgetallocation. About a minute
into the video Stewart is quite reasonably unsure of the role played by the
text in the 'th' element spanning this row:

 

<tr>

  <th colspan="4" class="tbhead" scope="rowgroup">

    State revenue

  </th>

</tr>

 

Stewart then asks an interesting question, "That 'state revenue' column --
could that be given a header attribute as well, so that it would say
'heading level 3, State Revenue,' to indicate to the person, ok, this is
actually like a subsection of this table?" 

 

So, this code (assuming he meant a heading element):

 

<tr>

  <th colspan="4" class="tbhead" scope="rowgroup">

      <h3>State revenue</h3>

  </th>

</tr>

 

It's never occurred to me to do that, but it validates. And testing in NVDA
I can skip from heading to heading in the table. 

 

Is this kosher? 

 

All the best,

 

Jeff Orchard

Information Analyst

Toronto, Canada