Do the results of studies generalize to new situations? For instance, suppose a study is conducted on a technique or intervention (e.g., providing health education to parents) and the study finds it to be effective for a particular outcome (e.g., improving the health of children). When the next study is conducted on (what appears to be) the same intervention and outcome, should we expect that study to ALSO find the intervention to be effective? There are a lot of reasons why it may NOT: ...