MICROENCAPSULATION OF ODORANTS AS A METHOD OF STIMULUS-CONTROL AND DELIVERY IN STUDIES OF ODOR QUALITY PERCEPTION

The judgment of odor similarity between members of pairs is preferable to odor naming in some situations. Similarity judgments are numerically summarized by multidimensional scaling (MDS) methods, which encourage the use of large numbers of pairs of odorants; but the presentation of many different odorants involves difficulties in stimulus preparation and presentation. The microencapsulation of odorants provides a stimulus presentation method for olfactory tests using nothing more than paper and pencil. This report examines the feasibility of the microencapsulated odorant as a stimulus procedure in MDS analyzed similarity judgments. In addition, the effects of repeated testing, both within and between test sessions was examined. Special attention was given to asymmetry of similarity perception. The new method of odor delivery proved to be excellent, and the MDS model produced was as expected. Systematic trends to judge pairs as increasingly similar over repeated judging, both within and between sessions, was observed. There were instances of asymmetry of similarity perception between the two orders of presentations of some odor pairs, but not others. The results suggested additional studies which will lead to a psychometrics of individual differences in odor quality perception. © 1979 Information Retrieval Limited.