Sometimes the whole is different from the sum of its parts.

I’ve been working on some research with Robb Dunbar of the University of Minnesota – Rochester that looks at using group or ‘pyramid’ exams as a cooperative learning technique.  In this model, students take each exam individually.  They then re-take the same exam cooperatively within a small group.   Their overall grade is a weighted combination of the two grades.

Analyzing this kind of data presents an interesting challenge.  The group’s score is not completely dependent on the individual scores.  The group members interact to determine their group answers in ways that can have significant effects on the group score.  In playing around with the data, I ended up creating a chart that highlights patterns in the data that were not visible with standard techniques.

The first thing to notice is that most students improved on the group test.  The other thing is that it looks like there are three types of groups:

Type 1: The group score is (more or less) equal to that of the highest individual.  This group may be characterized as having a strong leader – the highest scoring student asserts that his/her answers are correct and others follow

Type 2: The group score is less than highest individual score, but greater than all other individual scores in the group. This group may be characterized as having a negotiating leader – the highest scoring student asserts that his/her answers are correct but others may disagree.  The negotiated answer may not be correct.

Type 3: The group score is higher than all individual scores in the group.  This group may be characterized as one where everyone works together to figure out which answer is correct.  The highest individual score in this type of group tends to be lower than that of the other groups.  Maybe their strategy is the result of the recognition that no one student has all of the correct answers. 

Further research is needed to figure out if this pattern holds up and if the descriptions make sense.  However it is an interesting example of how visualization can reveal patterns that go unnoticed.

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