So right now I am shadowing a 8th grade science teacher at Drew Charter school and I was helping a student work on his idea come up with a science fair project. The student wants to study what kind of smells do dog's prefer over other's but using household (safe items), food, and dirty clothing. The student need to come up with a way to quantify his measurements. I was perplexed by how people measure smell (units?), so I suggested to him that he could do simple bean counting of dog's preferences from a large sample size (like 100 dogs) with 10 choices done in a random order. This got me wondering later about if their was prehaps a more concrete way to measure smell intensity and preference. In biology, is their a scientific way to quantify and measure smell? If so what are the units? Can it be measured by scientific equipment? Are common smells classified on a standardized scientific scale or taxonomic way to classify smell? If not then how do we know dog's can smell better? How do we say a smell is weak or strong? Any suggestion or comment would be appreciated.