There were seven "Comparison Tests" on Late Night and one on "Late Show." The first on Late Night featured Head Stagehand Tommy Casabona; the remaining segments featured Chris Elliott, with Gerard Mulligan assisting for two of them.

1. October 10, 1983: Tommy Casabona: margarine vs. butter
2. March 20, 1984: Chris Elliott: peanut vs. corn oil
3. April 26, 1984: Chris Elliott: packet vs. bottle ketchup
4. July 26, 1984: Chris Elliott: decaf brand #1 vs. #2
5. October 11, 1984: Chris Elliott: broiling vs. frying
6. July 14, 1989: Chris Elliott and Gerard Mulligan: satin finish vs. gloss
7. September 8, 1989: Chris Elliott: regular vs. improved dog food
8. January 31, 1996: Chris Elliott and Gerard Mulligan: beef fat vs. Olestra