The Environmental Reward Observation Scale (EROS): Development, Validity, and Reliability

Researchers have established a strong association between the frequency and duration of environmental reward and affective mood states, particularly in relation to the etiology, assessment and treatment of depression. Given behavioral theories that outline environmental reward as a strong mediator of affect and the unavailability of an efficient, reliable and valid self-report measure of environmental reward, we developed the Environmental Reward Observation Scale (EROS) and examined its psychometric properties. In Experiment one, an exploratory factor analysis supported a unidimensional 10-item measure with strong internal consistency and test-retest reliability. When administered to a replication sample, confirmatory factor analysis suggested an excellent fit to the one-factor model and convergent/discriminant validity data were supportive of the construct validity of the measure. In Experiment two, further support for the convergent validity of the EROS was obtained via moderate correlations with the Pleasant Events Schedule (PES; MacPhillamy & Lewinsohn, 1976). In Experiment three, hierarchical regression analyses supported the ecological validity of the EROS toward predicting daily diary reports of time spent in highly rewarding behaviors and activities. The EROS may represent a reliable and valid measure of environmental reward that may improve the psychological assessment of negative mood states such as clinical depression.