Meta-analysis of primary data

This chapter discusses statistical approaches to the meta-analysis of primary data in ecology and evolutionary biology. This type of meta-analysis is appealing for a number of reasons. Most importantly, each study can be analyzed in a consistent manner, thus producing directly comparable effect estimates that have been similarly controlled for potential biases and other study-specific issues. This avoids, for example, the problem of attempting to combine published effect estimates that have been adjusted for different covariates. Moreover, this type of analysis affords an opportunity to address other questions that typically arise in meta-analysis, such as the role of covariates, potential confounders, and alternative models that can be investigated using the primary data. This may not be possible when the analysis is only based on reported summary data. The chapter begins by addressing the important issue of collecting primary data in preparation for a meta-analysis