When is a meta-analysis useful?• Several compatible studies produce conflictingresults due to a type II error (i.e. lackingstatistical power, or small sample sizes and can’tbe generalized to the population at large)• To improve statistics power when study samplesizes are especially small.• To improve statistics power when study samplesize are especially small.• To improve estimates of effect size• When a large research study is too costly andtime consuming to perform