Question: Do you know of a search engine that allows me to filter research papers by sample size, study design, and methodology?

Consensus is an AI-indexed academic search engine covering more than 200 million papers across all fields. It offers proprietary search tools with filters for sample size, study design, methodology, and other attributes. That makes it a good choice for students, researchers and pros who need to speed up literature reviews and verify research.

Another useful tool is Semantic Scholar, which offers a powerful search with filters for journals, conferences, authors and paper types. It doesn't specifically mention sample size or study design, but its broad search capabilities and brief summaries (TLDRs) can help you evaluate papers and organize your notes.

Last, Epsilon has features like Investigate that offers summarized answers with inline citations, and Synthesize that generates detailed summaries from vetted papers. It's geared more toward synthesizing insights than filtering, but its large database and AI-generated content summarization can be very useful for researchers trying to extract and evaluate lots of information.