Find over 25,000 psychological definitions


lost letter procedure

an indirect attitude measure used at an aggregate group level. Two sets of stamped envelopes are created, one addressed to a group likely to adopt a particular attitudinal position on the target issue and the other addressed to a group likely to adopt the opposite position. Equal numbers of each version of the envelope are randomly distributed in a particular community. The procedure is based on the logic that a person finding a letter that has apparently been inadvertently dropped is more likely to place the letter in a mailbox if it is addressed to a group that shares his or her position. The percentage of people in that community supporting the two positions is then inferred from the number of envelopes that are ultimately mailed to each address. Also called lost letter technique. [originally developed by Stanley Milgram]

Browse dictionary by letter

a b c d e f g h i j k l m n o p q r s t u v w x y z

Psychology term of the day

February 25th 2025

single-case design

single-case design

an approach to the empirical study of a process that tracks a single unit (e.g., person, family, class, school, company) in depth over time. Specific types include the alternating treatments design, the multiple baseline design, the reversal design, and the withdrawal design. In other words, it is a within-subjects design with just one unit of analysis. For example, a researcher may use a single-case design for a small group of patients with a tic. After observing the patients and establishing the number of tics per hour, the researcher would then conduct an intervention and watch what happens over time, thus revealing the richness of any change. Such studies are useful for generating ideas for broader studies and for focusing on the microlevel concerns associated with a particular unit. However, data from these studies need to be evaluated carefully given the many potential threats to internal validity; there are also issues relating to the sampling of both the one unit and the process it undergoes. Also called N-of-1 design; N=1 design; single-participant design; single-subject (case) design.