Some areas in the sciences change rapidly. If up-to-date information is important in your research, look for indications that the information you are finding is indeed current enough for your purposes. You may have to rely on recently published periodical articles or other timely information sources.

Ask:
Is currency an issue in your research?
When was the information source published or last updated?
If the source is a web site, are links still valid? Outdated links are a sign of neglect.