What do sources mean when they say, 'I don't know' or 'I don't remember'? CREST Researcher Lorraine Hope categorises potential reasons for these hindering responses.

During an interview a source may respond to a question with either 'I don't know' or 'I don't remember'. This may well be a legitimate response. However, these responses may also reflect several cognitive, social and motivational states. Therefore, there are many reasons why a source might respond with an 'I don't know or 'I don't remember'.

Drawing on a range of published research, Professor Lorraine Hope has developed a taxonomy of the potential reasons for the 'I don't know' response, to explore, understand and inform in interview settings.

Through a series of posters, Professor Hope provides examples that illustrate each reason along with possible responses.

This poster focuses on reasons that relate to personal motivation, such as reluctance (through fear, or to protect others), status insecurity and ideological motivations (e.g., taboo, shame), or identifying as an 'informer'.

The other 5 posters look at other cognitive, social and motivational states:

  • Overview - a summary of the many reasons why a source would say 'I don't Know' or 'I don't remember'.
  • Memory Encoding - reasons that relate to factors at memory encoding, such as attention, distraction, reduced psychological capacity.
  • Memory Retrieval - reasons relating to memory retrieval, such as forgetting, uncertainty and metacognition, lack of retrieval support.
  • Interview Context - reasons relating to interview context, such as pragmatic communication, impression management and inferences about the interview.
  • Distrust, Cynicism and Hostility - reasons that relate to distrust, cynicism and hostility such as trust and control issues, perceptions of efficacy and deliberate deceit to mislead.
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Lorraine Hope is a CREST Researcher and Professor of Applied Cognitive Psychology at the University of Portsmouth.

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