dennis roberts wrote:
>
> as for the use of t tables ... or any other ...
>
> 1. one issue is can the student USE the table ... that is, you specify some
> from the table and you want to know if they can find it
Yes. That is, in my experience, students, small dogs, and most white
mice can use a t table, at least for values that actually turn up.
Interpolating loses a few students and the mice; the dogs and some more
of the students get worried about what to do for 90 degrees of freedom
if the table only goes to 60, or if t=16 and that df row only goes to
t=3.2
> 2. another issue is what the student knows about what happens in the table
> as df changes
Depends. They tend to know that the intervals get smaller as df gets
bigger, but many believe that Something Magic happens when n=60.
> 3. another issue is whether the instructor, when wanting to have t problem,
> HAS to have the entire table there ... why not just put a few selected
> values .... some right, some wrong ... that should be sufficient
Well, you don't HAVE to, but it makes the problem more realistic.
> 4. there ARE ways to have a t table large enough to be seen by a whole
> class ... sensible sized class that is
For this and the last one: the question is "why?" One legal sheet will
hold a perfectly good t-table.
> 5. there is always the situation of knowing that a t of approximately 2
> will get you results that are close
True, at the Holy 5% Level
> 6. tell em to bring in a 3 by 5 card ... i have done it for years ... and
> tell em to put anything on it they want ... they might put a few CVs on it
> ... as guidelines
No, I don't want them putting that sort of thing on. That card/sheet
is Sacred To The Important Things.
Finally, you can test *some* computer stuff without a computer by
copying a block of the session window into the word processor and
adding arrows and boxes saying things like "What is the null hypothesis
being tested here?" "What does this command do?" ...
-Robert Dawson
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