The semester is officially done. I finished grading my final
exams and submitted final grades to the registrar’s office yesterday. I picked
up my student course evaluations today to find out what the students thought about
my classes that they haven’t already told me. Today’s post will focus on my
first semester General Chemistry class where I’ve threaded an Elements theme
throughout the semester. The idea was to inject some creative work into the
course, and perhaps have the students wrestle with some of the basic concepts
as they design new Elements. For more context, click here for the previous update (in November).
The students turned in their proposals in mid-November. The
idea was to ensure they thought about the assignment beforehand and had some
idea what would go into their final poster. I tried to provide plenty of
feedback in the hope they would do a good job in their final posters. The key
missing part at the proposal stage was providing rationales for the properties
of their proposed element. Some examples: If it is a super-strong metal, why?
If it conducts electricity or heat, why? Why does it have the proposed melting
and boiling points? Will it react with oxygen in the air and why?
I was overall pleased with the results. The students did a
good job with their posters in both layout and presentation. I had a peer
review sheet where each student was assigned to visit the poster of a different
group. They had to rate the poster, presentation, and ability of the presenter
to answer questions. Each student was also required to present the poster to me
and answer my questions. (The students told me this was the most nerve-wracking
part.) They had prepared 2-3 minute talks for folks who visited the poster.
Because my class presented their poster at a symposium involving five other
classes (that were part of the Living Learning Community), student presenters
were also visited by other students not in the same class (but who lived in the
same residence hall) and also other faculty members.
There were some clever ideas from the students. One group
invented a super-heavy element for construction material that was strong yet
malleable, and to keep it stable, their new element had a “Jimmy Neutron” to
stabilize the large nucleus. Two groups went for light aluminum or titanium
analogs, one proposed new technology that used anti-neutrons to reduce the mass
by removing neutrons, and the other proposed a new element that could
accommodate 2d electrons (which could
only form bonds with other 2d
electrons). I was pleased to see students propose solid-state structures for
their compounds, and not just “molecular” Lewis structures. (They clearly
learned from one of the earlier scaffolding assignments.)
As in any group project, some students may be much more
knowledgeable than others, and the work is not always equally shared. From what
I can tell, only one group ran into some problems because one member wanted to
own the project and use only his/her ideas. However, that group ended up with a
good final poster and all its members were able to competently present the work
individually and answer questions, even some esoteric ones. In other groups, it
was clear who understood chemistry and who did not. From questioning the
students, there was a correlation between how the students were performing in
class and how well they could answer questions related to basic chemistry.
Overall, I think the New Elements project was successful.
The students had the opportunity to exercise some creativity. For some
students, this also strengthened their basic understanding – however I think
this clearly benefited the academically stronger students much more than the
weaker students. Overall, I think my scaffolding strategy worked, and provided
a thread throughout the semester. The majority of the students enjoyed the
project, even though they found it challenging, however a few thought it was
less relevant overall to learning the material in the class. (I had asked the
students specifically to say something about the project in the free response
section when they filled out course evaluations.)
However, I think there were some problems with the setup of
my class. Because of the New Elements thread, there were additional
assignments. Besides the online (Mastering Chemistry) homework due every class
meeting, I also had (themed) problem sets and scaffolded assignments related to
the final project. I could have reduced and spaced out some of the assignments
better, as there were some stressful periods for students, particularly if they
did not plan their time well. I also had take-home exams to give myself more
class time for the Elements thread, but I don’t think this worked well at the
end. Some students still worked together despite my telling them not to, and as
a result did rather poorly on the in-class final exam. The students who worked
independently as I instructed aced the final. I had a bimodal distribution on
the final exam.
While I had a small class and therefore a small sample size,
I think that the project work (in groups) allowed some of the weaker students
to skate by without as much impact to their grade throughout the semester, and
they did not prepare adequately for the take-home exams. (The exams were worth
2% of the overall grade and students got the full 2% regardless of how they
actually did on the exam.) I spent time before every exam reminding them how to
prepare for the exam and how to use it as a true “practice” under exam
conditions to see if they really knew the material. But I feel despite my best
efforts (and there were four exams), only the stronger students benefited. So I
think I will go back to in-class exams (worth more of the grade) during the
semester. This means I will have less class time, but I think this will lead to
better overall outcomes.
At the close of this semester, I’ve been thinking about the
cognitive load in my classes. The layering of the New Elements project
increased the cognitive load required of my students, and perhaps this is why
the stronger students thrived while the weaker students struggled. To some
extent this is true of all classrooms with mixed abilities, but the difference
between the two groups felt more stark this year, particularly after grading
the final exam. This is something I’ll need to think about more carefully as I
attempt a new theme in my non-majors class next semester. I’m excited for the
class, but I’m also reminded of the need to incorporate the lessons I’ve
learned. It’s a good thing to take some time at the end of the semester and
reflect on how things went.
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