"Two years ago we appeared to have discovered an exciting and enigmatic new predictor of success in a first programming course. We now report that after six experiments, involving more than 500 students at six institutions in three countries, the predictive effect of our test has failed to live up to that early promise. We discuss the strength of the effects that have been observed and the reasons for some apparent failures of prediction."
http://www.eis.mdx.ac.uk/research/PhDArea/saeed/paper3.pdf
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http://www.eis.mdx.ac.uk/research/PhDArea/saeed/