Re: [Phys-l] large class questions

["John Clement" <clement@hal-pc.org>]

I have not seen any studies for sizes 85 on up.  And I doubt that there have
been any.  Most studies of class size have been done with smaller classes
such as 24, and the ones I have seen have not shown the dramatic gains one
can get with PER.  Various things like McDermott tutorials, Modeling... all
need smaller sizes, but McDermott tutorials are implemented in amall
recitations which are often accompanied by a large lecture.  There is no
limit to the class size for the Mazur method, but his studies started with
students already at the formal operational level, and your course is
probably has a much lower intake.  I doubt there is much difference between
85 and 850, but there is a big difference between 85 and 25.

As to the comfort factor, the big factor is engagement, and other things
tend to have a much smaller effect.  But there is one size factor which does
have bearing.  Students need to do things like drawings, graphs,
explanations, and show how they solve problems.  With a larger number of
students grading such things becomes much more difficult.  The web based
assignments are not very useful except for numerical answers, and multiple
choice, both of which do not get the student engage with the necessary
tasks.  Notice that the Mazur method depends on essay or short explanations
which become more difficult to grade with larger classes.

Lab assignments can be added as web based assignments where the student
interacts with simulations.  But again, grading is problematic with large
classes.

Modeling was tried in a large lecture format, and it did not work very well.
This was reported at an AAPT conference a number of years ago.

John M. Clement
Houston, TX

> On 24 Sep 2008 at 14:53, Kilmer, Skip wrote:
>
> > The assumption that needs to be examined is whether when a teacher is
> talking to a group of students they are learning what (s)he thinks they
> are. PER has shed quite a bit of doubt on this assumption, no? If the
> students are not actively engaged in a dialog with the concepts they
> probably aren't learning very much.
> > Skip
>
> Obviously one needs to be doing something more than giving a passive
> lecture to have any impact on
> student learning.  Unfortunately, I'm not in a position to change my
> colleagues teaching approach.  My
> questions had to do with (1) does it make any difference to go from
> sections with 85 students to
> sections that have 120 or 140 students?  and (2) what effect does crowding
> in the classroom have
> regardless of class size on learning?   I think students would be more
> comfortable if we did not set the
> class limit using the number of available seats in the lecture hall.  We
> currently set our class limit at 85
> because there are 85 seats in the lecture hall.  I am one that gets 90
> percent attendance, generally, in
> my courses because I use various techniques to get high attendance.
> Whereas, others are less
> worried about attendance.
>
> David Marx
> Illinois State University