Heider’s Attribution Theory has been widely applied in education, law, clinical psychology, and the mental health domain. A fellow colleague, Weiner (1980), states: “Causal attributions determine affective reactions to success and failure. For example, one is not likely to experience pride in success, or feelings of competence, when receiving an ‘A’ from a teacher who gives only that grade, or when defeating a tennis player who always loses…On the other hand, an ‘A’ from a teacher who gives few high grades or a victory over a highly rated tennis player following a great deal of practice generates great positive affect.” (p.362). Students with higher self-esteem tend to attribute success to internal factors, such as luck and ability, while they contribute failure to internal factors such as effort difficultly. For example, students who consistently experience failure while completing a reading assignment are more likely to see themselves as being incompetent in reading. This self-perception of reading ability reflects the children’s expectations of failure while completing the reading assignment.While Heider was the founder of Attribution Theory, H.H. Kelley’s covariation model is the best-known attribution theory. This model was created for judging whether a particular action should be attributed to a characteristic or the environment, otherwise known as dispositional or situational. Covariation is the information that a person has from multiple observations of this person, at different times and situations, to form an observed effect and its causes. Kelley believes that when people make these hypotheses, we are acting like scientist taking into account three kinds of evidence. The first piece of evidence being consensus, the extent to which other people behave in the same way in a similar situation. The second, distinctiveness, the extent to which the person behaves in the same way in similar situations. Finally, the third, consistency, the extent to which the person behaves like this every time the situation occurs. These methods of evidence help support people attributing causality on the basis of correlation. This can explain why people put two things together, they assume that one causes the other. However, not knowing enough information can cause difficulties when making that kind of judgement. According to Kelley, people fall back on past experiences and look for either multiple necessary causes or multiple sufficient causes. Multiple necessary causes can explain the exact why the situation happened, while multiple sufficient causes can give multiple reasons as to why this situation happened.