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Re: WebAIM-Forum Digest, Vol 139, Issue 24

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From: Emma Duke-Williams
Date: Oct 27, 2016 6:36AM


Though you could argue as to whether the whole question is relevant to
someone who's severely visually impaired; would it be better to have a
multiple choice, but with 4 samples, and get the student to identify
which one was quartz by feel, as that's the way they'd have to do it
were they in the field - and is probably more equivalent to the rest
of the class going from the visual appearance of the rock, rather than
a complex description.
Of course, then the instructor probably wouldn't want to have diamond
as one of the choices as Cliff had suggested...
Or, give them all a description, if you want them to know particular
properties of the rock, rather than just what it looks like.

Emma

> Today's Topics:
>
> 1. Re: ALT text usage for Geology test questions
> (Tyllick,Cliff S (HHSC/DADS))

> ----------------------------------------------------------------------
>
> Message: 1
> Date: Tue, 25 Oct 2016 23:28:30 +0000
> From: "Tyllick,Cliff S (HHSC/DADS)" < <EMAIL REMOVED> >
>
>
> Quartz is:
>
> a) the plural of “quart” in German.
>
> b) a subatomic particle, distinguished in part by its charm.
>
> c) a hard white or colorless mineral consisting of silicon dioxide, found widely in igneous, metamorphic, and sedimentary rocks. [The correct answer is always “c,” right?]
>
> d) All of the above.
>
> e) a) and c), but not b).
>
>
>
> So let’s think of how we can present the information in the image as a question, not an answer. (Gee, we’re playing alt-Jeopardy! – with apologies to people not familiar with the game show.)
>
>
>
> Here are points I would consider:
>
> · Does anything in the image tell me that the substance is hard? If not, don’t use that word. Maybe it has sharp edges, and I can infer from those that it is hard, but I can’t “see” hardness. So if sharp edges is a clue I should be looking for, tell me that they’re there—but don’t tell me what they mean, because presumably you’re testing for that.
>
> · If anyone can tell it’s silicon dioxide by looking at it, keep them away from kryptonite! I don’t know geology, but I do know X-ray crystallography, and it would take X-ray vision and sophisticated software to tell what elements are in a crystalline substance. So obviously that isn’t helpful in the alt text.
>
> · The definition says quartz is “found widely in igneous, metamorphic, and sedimentary rocks.” But is the rock in the image all three of those? Presumably it’s mainly one or two. What features would I have to perceive in the image to determine which one—or ones—are present? In the alt text, describe those features—but don’t give away the meaning.
>
> · If the image is a chunk of quartz completely isolated from the source rock, how would I know what kind of rock it came from? I assume that I wouldn’t. But if there is something telltale that suggests this is quartz from a particular type of rock, describe that feature in the alt text—but don’t tell what it means.
>
> · What’s the point of the ruler? Yes, I know it establishes scale, but what is that scale? Is the ruler calibrated in millimeters? Centimeters? Sixteenths of an inch? Some other base unit? Then give me that information, as presented by the ruler. In other words, you could say “11.4 mm wide” if the ruler is calibrated to the millimeter, but you couldn’t say “11.39 mm wide”—so convey significant digits and estimations to the extent that would be standard in this field.

>
> You could do both. What if you set the problem up so the student had to identify quartz from a collection of crystal-forming substances? I’m going out on a limb with my geologic knowledge, so indulge me if the specific examples don’t make perfect sense. It’s the approach that matters:
>


--
Emma Duke-Williams:

Blog: http://emmadukewilliams.co.uk
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