My notes regarding the students’ understanding of eclipses indicate that the demonstration is helpful to
their understanding. Although several students continue to err on Question 1, I believe this is because they
forget which body "disappears" during the eclipse in question. This fall, I will ask them to come up with
mnemonic devices and share them with the class. Incorrect answers to Question 2 are due to a lack of
remembering basic facts. I am pleased to see that most students are able to answer Question 3, which
indicates that they have understood the demonstration and that it helps their spatial visualization of the
situation as viewed from a different vantage point. I have not asked Question 4 yet; I probably will ask it
on an assignment first because that will enable me to assist the students with their answers if necessary,
and I can assess whether the question is a fair one for an exam.
I plan to evaluate formally the demonstration’s effectiveness by administering