The Desperate Need for Replications

An overemphasis on creativity for evaluating research has lead to a serious devaluation of replication studies. However, we need a total sample size of N = 153,669 to estimate a causal effect to two digits, which is quite rare for a single study. The only way to get accurate estimation is to average across replications. If the average sample size were as high as N = 200, we would need over 700 replication studies. Scientific replications are more problematic than pure statistical replications, and so we need even more replications to achieve reasonable accuracy. Copyright 2001 by the University of Chicago.