Is it true when a website ends in .com its probably not a good site for research.?

It's not inherently true that a website ending in .com is unsuitable for research. While many commercial sites (.com) may prioritize marketing over factual content, some reputable organizations and educational resources also use .com domains. It's essential to evaluate the credibility of the specific website, considering factors like the author's expertise, the quality of sources cited, and the site's overall purpose, rather than just the domain extension.