Published online by Cambridge University Press: 31 July 2008
This study employed similarity judgments to determine the dimensions used in distinguishing between methods of contraception, and to investigate individual differences in the use of these dimensions. Three groups of subjects rated the similarity of seventeen methods of contraception, and also rated each method on a number of adjective scales. Multidimensional scaling of the similarity judgments revealed two dimensions: one related to effectiveness, expense, and safety, and the other differentiating between standard and non-standard methods of contraception (or natural and non-natural ones). In addition, methods of contraception were arrayed in the space mainly on the basis of physical similarity. Analyses of the rating scales indicated that subjects perceived methods accurately in terms of effectiveness, but were inaccurate in their ratings of safety to the user. Finally, analysis of individual differences indicated that the second dimension was more salient to younger than to older subjects, but did not reveal differences related to religion or contraceptive use.