Research in debate will often need scholarly and academic research. This evidence can be hard to find from a simple Google search, so it's important to become familiar with how to use Google Scholar, Google News, Jstor, or other databases.
For our purposes, we'll limit our academic research to Google Scholar, where most of the content is geared toward academic journals. This means that experts in their respective fields are publishing information that has undergone peer review.
Peer review involves experts critiquing the work of others to ensure that the research methods deployed are valid and that the results are reliable. The information you will find on Google Scholar will likely be more credible and reliable than that featured in a general web search. This also means that some of the information may be difficult to read and comprehend without more background. The deeper you dive into the research, the more you will come to read and understand articles found on Scholar and similar search engines.