A concept map diagrams ideas and their relationships. Karpicke and Blunt’s report (published online January 20, 2011) described Experiment 1: 80 Purdue undergraduates, 20 assigned to each of four groups. Chance assignment was not stated. Focusing on two groups, both studied one 276-word science text for 30 minutes. Mapping used five minutes reading and 25 making/reviewing a map with the text available. The other group read, typed what they remembered, reread and recalled again. One week later, recall/rereading scored higher on a test of stated facts and conclusions drawn from that text. Interpretation: equal time did not isolate diagram format; this compares activity bundles.