A "comparative study" means examining and analyzing different things or ideas to understand their similarities and differences. It involves comparing and contrasting multiple subjects or topics to gain insights and draw conclusions. Full definition
The emphasis will be on comparative studies of different technology stages under comparable boundary conditions. (occup-med.biomedcentral.com)
This striking parallel will be further investigated in direct comparative studies on dogs and children. (sciencedaily.com)
Only from the weight of evidence provided by comparative study of many information sources, can one hope to reach a convincing conclusion. (outersite.org)