The researchers investigated the comparative effects of individually-constructed and collaboratively-constructed computer-based concept mapping on middle school science concept learning. One hundred and sixty one students completed the entire study. Using prior science performance scores to assure equivalence of student achievement across groups, students were assigned to three groups: a self-selected study strategy group, an individual-concept mapping group, and a collaborative pairs--concept mapping group. Collaboratively and individually-constructing computer-based concept maps had equally positive effects on seventh grade middle school science concept learning as measured on a comprehension test. However, the students who collaboratively constructed concept maps created significantly higher quality concept maps than those who individually constructed concept maps indicating deeper conceptual understanding. (Contains 2 figures and 4 tables.)