Discourse analysis involves more than simply conducting interview studies. Rather, it examines how talk involves and reinforces underlying social issues such as power and control. Discourse can take many forms, and studies of discourse include written exchanges, internet communications, symbolism and semiotics, media reports and social directives as well as conversations. One important function of discourse is communicating social attitudes and developing or establishing social explanations. The criticism of covariance theory is related, and concerns the social nature of the attributional process. Attribution theory analyses explanations at the individual cognitive level, whereas social representation theory looks at the overall social and societal level of explanation. Correspondent inference theory explores the different factors which contribute to the inferences which people make about social responsibility. Many of the social representations which are in common currency consist of traditional knowledge, which has been passed on through the family or through social institutions.