Question: 1. What would you consider reasonable when attempting to find all possible studies to be included in your meta-analysis? Should you contact original authors if you find a relevant study but the article does not include enough information to compute an effect size? Would you only include studies that provide effect sizes in their articles, or at least enough information to compute them? What if there are several studies that appear to support your hypothesized relationship between variables, and you decide to contact the original authors to obtain effect size data from them. Would you also need to contact the original authors for an equivalent number of studies that do not support your hypotheses and do not provide effect sizes?
2. What is the file drawer problem? Suppose you find a very strong meta-analytic result. Should you worry about it? What if the result is just moderate? Or small? What determines the potential severity of the problem?