Regents Recap — June 2012: Some Improvement

Here is another installment from my review of the June 2012 New York State Math Regents exams.

I tend to be rather critical in my evaluation of these exams, pointing out poorly constructed, poorly phrased, and mathematically erroneous questions.  However, there have been some minor improvements of late.

First, it seems as though, in general, the wording of questions has improved slightly.  To me, questions on the June 2012 exams were more direct, specific, and clear than in the recent past.

There were also some specific mathematical improvements.  For example, although graphs were often unscaled, they seemed generally more precise, avoiding issues like this asymptote error.

There were considerably fewer instance of non-equivalent expressions being considered equivalent.  The problem below avoids the domain-issues that plagued recent exams.

Perhaps it’s just luck, but we’ll give the exam writers the benefit of the doubt for now.

And the Algebra 2 / Trig exam definitely demonstrated a more sophisticated understanding of 1-1 and inverse functions, which is good to see in the wake of this absolute embarrassment from last year.

Perhaps someone has been reading my recaps?

Let’s hope we see continued improvement in the clarity and precision of these exams.  If these exams are going to be play such an important role in today’s educational environment, it seems of utmost importance that they be accurate and well-constructed.

Regents Recap — June 2012: Spot the Function

Here is another installment from my review of the June 2012 New York State Math Regents exams.

Below is a problem from the Integrated Algebra exam.  Which of these graphs represents a function?

Have you identified the function?  Well, you’re right, because all of these graphs could represent functions!

What the question presumably intends to ask is “Which of these graphs represents y as a function of x?”  Under this interpretation, the correct answer is (1).  But in (2), we see a graph that represents x as a function of y.  So it, too, represents a function.

Indeed, even graphs (3) and (4) could represent parametric functions.  For example, (4) could be written.

r(t) = < 4 \thinspace cos(t) , 3 \thinspace sin(t) > , 0 \le t < 2\pi

This plane curve is a function of t.

I doubt this makes much practical difference in the outcomes on this exam, but precision is important in mathematics; it should be modeled for students on official assessments.  And those writing these important exams should be familiar enough with the content to write precise and accurate questions.

Regents Recap — June 2012: Throwing Darts

Here is another installment from my review of the June 2012 New York State Math Regents exams.

Below is a problem from the Integrated Algebra exam that highlights the artificiality of so-called “real world” problems.

In order to solve this problem in a high school algebra class, a crucial assumption must be made, namely, that every point on the target is equally likely to be hit.  This means that the dart is just as likely to hit a spot near the bulls-eye as any spot near the edge.

Math teachers end up spending a lot of time training students to make these assumptions, probably without ever really talking explicitly about them.  It’s not necessarily bad that we make such assumptions:  refining and simplifying problems so they can be more easily analyzed is a crucial part of mathematical modeling and problem solving.

What’s unfortunate is that, in practice, students are kept outside this decision-making process:  how and why we make such assumptions isn’t emphasized, which is a shame, because exploring such assumptions is a fundamental mathematical process.

Is it a reasonable assumption that every point is equally likely to be hit?  Well, if the thrower is skilled, the dart is probably more likely to land near the bulls-eye.  Would gravity make the lower-half more likely than the upper half?  Discussing these, and other relevant factors as part of the modelling process can be engaging, fun, and highly mathematical.

But when standardized tests with “real world” problems are the focus of education,  students usually end up getting trained to not ask these questions.

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