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A. John Mallinckrodt Cal Poly Pomona ajm@csupomona.edu. Making use of Rarely Given Wrong Answers on the Force Concept Inventory. The Problem. Many administer the FCI in ungraded, “credit for completion” mode. How do we establish that the test has been taken in good faith?. One Solution.
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A. John Mallinckrodt Cal Poly Pomona ajm@csupomona.edu Making use ofRarely Given Wrong Answers on theForce Concept Inventory
The Problem • Many administer the FCI in ungraded, “credit for completion” mode. • How do we establish that the test has been taken in good faith?
One Solution • Have a way to identify exams that are not taken in good faith and … • … tell the class about it!
Rarely Given Wrong Answers • The FCI has a large number of distractors that are rarely chosen by students—RGWAs • Random choice leads to an anomalously high occurrence frequency for RGWAs
Defining RGWAs • Choice of database • Large set of previous results • Current cohort • Choice of frequency(My “discriminator” = 1/f = minimum number of exams expected to yield one instance of the specific RGWA)
Procedure • Collect frequencies for all answers • Decide on a set of RGWAs • Determine expected number of RGWAs • For random guessing (=Total number of RGWAs/5) • For good faith effort (= Sum of p’s for each RGWA) • Compare with individual results(Note: We can always expect random guessing to produce 6 correct answers.)
Now what? • To confront or not to confront? • To deny credit or not to deny credit?
Conclusions • RGWAs seem to provide a relatively robust method of identifying bad faith efforts • Still needed • Larger databases • Better statistical analyses • More user-friendly (user-friendlier?) interface • Interest from FCI community (?)
A. John Mallinckrodt Cal Poly Pomona ajm@csupomona.edu Making use ofRarely Given Wrong Answers on theForce Concept Inventory