Final answer:
The purpose of examining research design validity includes establishing the generalizability of findings, identifying potential threats to validity, and considering alternative explanations. However, judging the credibility of the researcher is not part of this process.
Step-by-step explanation:
The purpose of examining the validity of a research design involves several key objectives to ensure the integrity of a study. This includes determining the generalizability of findings, which relates to how well the results can be applied to contexts outside of the study. It is also important to identify threats to validity, which may include various biases or errors that can compromise the quality of the research. Another significant element is determining if rival hypotheses or alternative explanations for findings might be plausible, providing a comprehensive understanding of the studied phenomenon.
However, judging the credibility of the researcher is not the purpose of examining the research design's validity. While researcher credibility may affect the perception of the study, it is not an inherent aspect of the research design itself. Therefore, this option does not fall under the aim of assessing a study's validity.