Fresh as a daisy: Within‐person associations between sleep, vitality, and self‐ and other‐rated job performance

Summary From a resource perspective, employees' sleep quality, sleep duration, and feelings of vitality are believed to predict important work‐related outcomes. However, many studies ignore the dynamic nature of the constructs or rely primarily on self‐reported data. Including both self‐ and other‐ratings of daily job performance, we examined the extent to which daily sleep quality and duration predict daily job performance, and whether these relationships are mediated by vitality. Student teachers ( N = 165), internship supervisors ( N = 97), and students (i.e., targets; N = 69 classes) participated in an experience sampling study with morning assessments of sleep duration and quality ( n = 1,762 and n = 869), and two daily assessments of vitality ( n = 2,207) and performance (self‐, supervisor‐, and target‐rated; n = 2,160, n = 1,113, and n = 1,087). Multilevel path analyses suggested that 1) sleep quality but not duration predicted individuals' vitality and self‐ and target‐rated job performance, 2) vitality was positively associated with performance according to each rating source, and 3) midday vitality did not predict afternoon performance, nor did it mediate the relationship between sleep and afternoon performance. Implications for theory and practice are discussed.