August 30, 2016

A better way to give practice problems?

Is it better to do traditional physics problems...or would there be value in structuring problems so that the answer is stated in the problem?

For example, when I think of a "traditional" physics problem, I think of something that looks like this:
If air resistance is negligible, determine the maximum height (above its release point) of a ball that is thrown straight upward which is in the air for a total of 3.0 seconds. 
But, what if the problem were stated more like this:
Show that when air resistance is negligible, a ball thrown straight up that is in the air for 3.0 seconds reaches a maximum height of 11 meters above its release point.
In my mind, the second version explicitly puts emphasis on the process and the reasoning behind the process, whereas the traditional problem naturally emphasizes the answer to the question.  I can see this way being done in the classroom setting, for homework practice as well as assessment purposes.

What am I missing here?  Why isn't this done for intro physics classes?


Anonymous said...

What's missing for me is the opportunity to assess how a student judges the reasonable-ness of the answer they come up with. Of course not all students do that but it's great to see when they say something like "wait a minute, that can't be right." Of course that's going beyond them demonstrating the ability to put the concepts together, so I guess it depends where it land in your priority list.

Mr. Lamore said...

The second way (Show that...) is how many IB questions are structured. The additional challenge is for the teacher who now has to follow the students' work. Some magically arrive at the answer, some maybe arrive at the answer. Students get skilled at subtly obscuring their work.

Andrew said...

Those are GREAT criticisms - which is why I would try to not use this method exclusively. Especially with regard to the matter of obscuring solutions, I would emphasize that being clear with the work is more important than getting to the answer, since they already have the answer. But, your point is totally valid.