Harold Kelley's covariation model (1967, 1971, 1972, 1973) is an attribution theory in which people make causal inferences to explain why other people and ourselves behave in a certain way. It is concerned with both social perception and self-perception (Kelley, 1973).Low Consensus, Low Distinctiveness, High Consistency = Personal Attribution High Consensus, High Distinctiveness, High Consistency = Stimulus Attribution High Consensus, Low Distinctiveness, Low Consistency = Circumstance Attribution Harold Kelley's covariation model (1967, 1971, 1972, 1973) is an attribution theory in which people make causal inferences to explain why other people and ourselves behave in a certain way. It is concerned with both social perception and self-perception (Kelley, 1973). The covariation principle states that, 'an effect is attributed to the one of its possible causes with which, over time, it covaries' (Kelley, 1973:108). That is, a certain behaviour is attributed to potential causes that appear at the same time. This principle is useful when the individual has the opportunity to observe the behaviour over several occasions. Causes of an outcome can be attributed to the person (internal), the stimulus (external), the circumstance, or some combination of these factors (Hewstone et al., 1973). Attributions are made based on three criteria: Consensus, Distinctiveness, and Consistency (Kelley, 1973).