The Critical Incident Technique (CIT) uses the individual experience of  the respondent and focuses  by way of asking open questions on  event-specific examples of the perceived quality of consumers. The  incidents relate to a significant contribution to the perceived quality  in a positive or negative way (non-routine quality). The respondents can use their own words to describe an event that was a specific ‘good’ or  ‘bad’ experience. The data that are collected in this way are detailed  and profound.
Critical incidents are not only important as indicator of the evaluation of processes by the customer. They can also explain  the behaviour of the customer. For instance, Strauss and Hentschel  experienced that 42% of exit-behaviour by customers of car-dealers was  directly linked by a negative experience. On the other hand positive  experiences can lead to more consumption of products or services.
Critical incidents can be categorised. A major difference with the measurement  on attributes is that one does not feel forced to give an opinion about  any given attribute. The focus is on experiences from the past that  really occurred and one can vividly remember. This makes the questioning less artificial. After collecting these experiences a  classification  is made. And the respondent really has the feeling that he/she has said  that what is important.