This article reports the results of a series of experiments to determine optimum forms and procedures for collecting information on frequent nondurable expenditures. A diary arranged by product groups resulted in higher cooperation and better reporting of expenditures than did either journal or outlet type diaries. Both cooperation and reported level of expenditures dropped as the length of the reporting period increased, but the drop was lowest on the product diaries. Use of a gift increased cooperation and level of reporting. An experiment with tape recorders also produced promising results and seemed to offer a means of collecting such data from people not receptive to diary methods.