There are some questions which are either wrong, irrelevant, or ambiguous.
1. Objective 5 #2 Which of the following is directly proportional to an
objects mass.
Answer: inertia
As far as I know physics texts to not generally equate inertia to mass.
Inertia is generally treated as a concept rather than an exact quantity.
Can anyone cite a generally accepted law where inertia is used as an exact
quantity? I consider this a factoid used so teachers can ask questions on
tests. How about a real answer such as momentum.
1a. Objective 1 #3 The answer is A, but wouldn't C also be a correct
answer?
2008 exit level
1b. Objective 3 #5 - This one makes me uneasy as to what they are really
testing. If the student notices the "pneu" prefix they will know it is for
respiration. The fact that it is not under water eliminates one answer, but
the other answers might by a long stretch be possible. Since I know that
trees generally are flowering plants where the flowers are on the branches
and that leaves are the food producers, I would reject the wrong answers.
But there are many strange variations in plants and animals and ways of
functioning that defy the common knowledge.
2. Page 5 - Juicer - This is an ad with the "hypothesis" that juicer
provides "A tasty way to good health". The experiment is essentially a
taste test of juices made by juicer vs canned juices. The assumption of
course is that vegetables are healthy foods. The table basically says that
juicer juices taste better, but there is one entry where juicer juices are
called healthy and canned juices are not. The student has to decide between
4 reasons why the experiment does not confirm the hypothesis so the
advertisers claim could be rejected.
Assuming the table is based on actual taste tests, the canned juice
certainly loses. But the claim that canned juice is not as healthful is an
obviously bad conclusion. So is it
A Unclear instructions, B Poor experimental design C Weak hypothesis, D
contradictory data
I would say none of these fit the bill and the real problem is an invalid
conclusion on one item. They claim it is B, but I would say the test if a
real one does show that juicer produces a tasty way to consume vegetables.
So the claim of tastiness may be accurate. The hypothesis did not include
juicer as producing better health than canned juices.
To my mind the real answer is "This is a crappy question"
3. Objective 4 #1 shows 4 cubes in water. 3 are floating W. 60%
submerged, X 90% submerged, Y: sunk to bottom, Z: 40% submerged. The
students are given 4 densities:
A Balsa 0.12, B Ebony 1.22, C Maple 0.67, D Poplar 0.42
They ask what material is Z made of.
Anyone who knows a little about the math of floating would conclude that Z
is Poplar, but the approved answer is Balsa. So if students just conclude
that the highest floating one has the least density this would be correct,
but Balsa would float with only 12% submerged, not 40%.
The really good students in physics will pick the "wrong" answer and the
medium ones will pick the approved answer. Now if the test designers had
understood the physics they might have the blocks float at the correct
levels, but the drawing may have been made by an anonymous artist who did
not have the knowledge and it was not parsed carefully.
Many of the questions are straight forward memorization with others
requiring some modest interpretation. #3 on my list has a few elements of
being a very good question. What if they gave the students a bigger table
of materials say with 6 to 8 items. Now it requires very good analysis.
But it misses the big mark. The McDermott question is the deeply conceptual
one where the students have to draw where various objects would float and
most of them sink. Students who don't understand floating will have things
with density slightly higher than 1 floating in the middle and not totally
sinking. The McDermott question requires no tricky analysis, just
understanding. The TAKS question relies on just knowing one fact that high
density sinks and low density floats, then just picking the one with the
lowest density. It is a very low level question.
Of course when they have poor questions, they never acknowledge it, and do
not regrade. They release the questions and do not provide notes as to the
validity of the questions. Often if you look up the objectives they may not
match what the questions are actually testing.