Human error (slips and mistakes)
James Reason (1990) has extensively analysed human errors and distinguishes between mistakes and slips. Mistakes are errors in choosing an objective or specifying a method of achieving it whereas slips are errors in carrying out an intended method for reaching an objective (Sternberg 1996). As Norman (1986) explains: "The division occurs at the level of the intention: A Person establishes an intention to act. If the intention is not appropriate, this is a mistake. If the action is not what was intended, this is a slip."