Accurate processing of information about outcomes is no simple task under the variable conditions of everyday life... usually, many factors enter into determining what effects, if any, given actions will have, Actions, therefore, produce outcomes probabilistically rather than certainly. Depending on the particular conjunction of factors, the same course of action may produce given outcomes regularly, occasionally, or only infrequently

Social foundations of thought and action: a social cognitive theory (ed. Prentice Hall, 1986)