Abstract
The study of drug interactions presents investigators with questions about both experimental design and interpretation of results that easily can become complex and confusing. Among the advantages of the isobolographic method is that it leads to rational experimental design and renders both the descriptive and analytical considerations of results obtained relatively simple and straightforward. In particular, the descriptive use of the method is such that it permits experimenters to express compactly and unambiguously the salient features of the observed interaction.