NIT PICKER'S SPECIAL!
... not enough data provided ....
Philosophical and pedagogical remark:
There seems to be quite a lot of nit-picking on this list. Similarly, many
exercises in textbooks are spelled out in great detail to avoid students
complaining there is "not enough data provided".
Some of this serves a purpose, but overall I think it does more harm than
good, for multiple reasons:
1) We should keep in mind that someone who answered "not enough data
provided" on a job interview would certainly not get the job. This applies
to real research jobs as well as industrial/technical jobs.
In the real world, one virtually _never_ gets a question or an assignment
where all the required data is provided on a silver platter. Make sure
your students understand: Their job (if they want to have a job) is to
figure out what data is needed, track it down, and then answer the
question. As a last resort, if there's some factor that is important but
can't be tracked down, give an answer in the form of an equation or a graph
that communicates the dependence.
Anecdotes:
a) On a quiz I once asked a bunch of Ivy League college students (juniors
and seniors) "what are the length, width, and height of a typical
one-gallon milk jug" and I got all kinds of objections: "You didn't teach
us the density of milk, you didn't teach us how many liters there are in a
gallon, you didn't specify whether the jug has rounded corners, moan, moan,
whine, whine...."
My response was to say, "If any of you has never seen a one-gallon milk
jug, raise your hand..... OK, apparently you've all seen such a
thing. Well, how big was it? The point here is that when somebody asks
you a question, you should bring to bear _all_ of the information you
possess, not just the information that was covered in Chapter 3."
b) When Arno Penzias was VP in charge of research at Bell Labs, he was fond
of making a similar point. He would ask people "About how much water flows
out the Mississippi River?" Typically people would say "I have no idea"
whereupon he would shout "You must have SOME idea! Figure it out!" and in
fact it is child's play to figure out a pretty darn good estimate. The
word got around that when Arno asks a question, you had better not say "I
have no idea."
c) When I'm teaching pilots how to properly land the airplane, I tell them
that if the airplane's current weight is 30% less than the max certified
weight, the approach speed should be 15% less than the number given in the
handbook. Sometimes people grumble about this. They complain "it doesn't
say anything about that in the FAA-approved Pilot Operating Handbook that
came with the airplane. We're going to get in trouble for using an
unapproved procedure." My response is to say that the POH is not holy
scripture, and laws of physics are laws of physics whether they're
mentioned in the POH or not. The FAA greatly prefers that we make
allowance for current weight, rather than coming in 10 knots too fast and
running off the end of the runway.
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2) I somewhat regret rephrasing my bus-arrival puzzle to make it more
resistant to nitpicking.
Indeed I wish at the end of every chapter of every textbook, there should
be at least one problem that is underspecified, requiring the student to
bring to bear information _not_ specified in the problem, or the chapter,
or even the entire book.
By the same token, one should be careful with questions such as "how much
dirt is there in a hole 3 feet by 6 feet by 10 feet" where the conventional
answer depends on a nit-pick. One should emphasize that it's a joke, and
the conventional answer is only appropriate in joke-land, not in the real
world.
Some people will complain that it's not fair to ask students to know
something I haven't taught them. I say just the opposite: It's unfair and
unwise to give students the impression that they can get through life
nit-picking and/or refusing to answer underspecified questions.