When conducting your own research, you'll need to find other research in that field that has been previously published. You'll need to critically evaluate previous research positively or negatively in order to place your own research in context. If you are extending a previous study, you'll need to provide some rationale about why you are doing so. If you are coming up with some new approach, you'll need to provide a logical explanation for why previous research is not sufficient. Evaluating research allows you to prove that you can competently think critically about topics in your field of study.
Look where the research is published. If the research is published in a peer reviewed journal in your field, you can typically trust that the research conducted is up to the field's standards. If it's published in a magazine or other publication that has a large amount of advertisements, the research may not be credible.
Determine if the research has a strong purpose and relevant research questions. You should be able to read the abstract or introductory section of the research article and find the research question. Once you've found the research question, decide whether it is relevant or interesting.
Read the results and discussion section of a research article to determine if the research questions were actually answered. If they weren't answered, the research may not be credible or important.
Evaluate the methodology. Determine if the data used were relevant to the research question. Also be sure to look at the way the data were collected. For example, if data should have been collected from a random sample, but it was not, the results of the research could be flawed.
Read the discussion section and the conclusion. Look for instances where a researcher makes overarching claims that the research can't support. In these cases, the research may not be credible.