Exploratory and confirmatory factor analyses of probability discounting of different outcomes across different methods of measurement.

The present studies used exploratory and confirmatory factor analyses to explore the degree to which probability discounting processes are similar to delay discounting processes. To determine whether these processes are similar, 2 questions were addressed: the degree to which probability discounting outcomes can be categorized into multiple domains (as demonstrated for delay discounting) and whether the inverse magnitude effect would be observed for nonmonetary outcomes. An exploratory factor analysis was conducted using data from the fill-in-the-blank method (Study 1), followed by a confirmatory factor analysis using data from a multiple-choice method (Study 2) as a replication. These studies provide support for the idea that outcomes can be subdivided into multiple domains. Generally, the discounting rates were steeper for tangible outcomes than nontangible outcomes, and a magnitude effect was observed that was consistent with, rather than the inverse of, that observed for delay discounting tasks. Complexities related to the relationship between probability discounting processes and delay discounting processing are discussed.