Single Item Measures in Psychological Science: A Call to Action

Single-item measures have a bad reputation. For a long time, adopting single-item measures was considered one of the surest methods of receiving a letter of rejection from journal editors (Wanous et al., 1997). As one research team noted, “it is virtually impossible to get a journal article accepted ... unless it includes multiple-item measures of the main constructs” (Bergkvist & Rossiter, 2007, p. 175). However, a series of articles published in the late 1990s and 2000s began to challenge the conventional view that single-item measures are an unsound approach to measuring cognitive and affective outcomes (Bergkvist & Rossiter, 2007; Fuchs & Diamantopoulos, 2009; Jordan & Turner, 2008; Loo, 2002; Nagy, 2002; Wanous et al., 1997). These articles did much to alleviate the stigma surrounding single-item measures, but even today, many researchers remain unconvinced that single-item measures can provide valid and reliable assessments of important psychological phenomena. Of course, there are many instances in which single-item measures would be a poor choice – for example, in research aiming to capture the breadth of human personality or emotion. However, when a construct is unambiguous or narrow in scope, the use of single items can be appropriate and should not necessarily be considered unsound (Wanous et al., 1997). The last few decades have seen a marked increase in the use of large national-level panel data in psychological research. Given the considerable volume of data and the diversity of constructs included in these panel surveys, it is often necessary to measure psychological constructs using just a few or even only one item. For example, the Household, Income and Labour Dynamics in Australia Survey (HILDA; Watson & Wooden, 2021) assesses body weight satisfaction using the single item “How satisfied are you with your current weight?” with response categories of 1 (= very satisfied), 2 (= satisfied), 3 (= neither satisfied nor dissatisfied), 4 (= dissatisfied), and 5 (= very dissatisfied). Although there are multi-item measures of body satisfaction available, on face value, there is no reason to think that this single item does not adequately capture a person’s general satisfaction with their body weight. The increasing use of large panel surveys in psychological research means that now more than ever, it is essential to ensure that single-item measures are valid and reliable. (PsycInfo Database Record (c) 2022 APA, all rights reserved)