Mind map: What sources mean when they say "I Don't Know"

Motivation and strategy

Personal motivation

Example:

• I’m afraid/I feel trapped or under pressure
• I was asked to keep it a secret/don’t want anyone to find out
• I need to protect some people close to me

Explanation:

• Revealing the information may bring other people into the investigation/put other people at risk/betray friends or family
• Ideological or group allegiances

Response:

• Acknowledge and provide assurances (where possible)
• Explore issues and concerns
• Develop rapport and trust, highlighting the benefits of disclosed information
• Reframe: not a secret, not a betrayal; benefits others, still within in-group

Distrust, cynicism, and hostility

Example:

• I don’t trust you with this information
• You might use this information against me

Explanation:

• Doubts about the interviewer's intentions towards them or their ability to look after their safety
• A perception of loss of control and they are entering a process that once started cannot be stopped

Response:

• Rapport, acknowledge, assurances (where possible)
• Develop rapport and trust, highlighting the benefits of disclosed information
• Explore issues and concerns
• Explain processes for information security and source protection

Memory and cognition

Memory encoding

Example:

• I was intoxicated/high
• I was extremely tired/disoriented/feeling confused

Explanation:

• May not want to admit to self-inflicted states or perceived weaknesses
• Worry that admitting to these states may make them appear incompetent or unreliable

Response:

• Establish what the state at encoding was – but do not dismiss memory
• Use memory-enhancing techniques (mental reinstatement of context, open-questions, free report)
• Avoid leading questions, option-posing, suggestions

Memory retrieval

Example:

• It happened so many times I’m not sure what exactly happened on the occasion

Explanation:

• Difficulties with particularisation of a single instance when distinguishing between similar events (e.g. repeated abuse, domestic violence)
• Problems identifying the source of a particular memory (source monitoring)

Response:

• Ensure clarity when questioning about repeated events
• Use methods that might assist discrimination between repeated events (specific dates, times, details or temporal placing, i.e. ‘the time before last’)
• Seek particularisation (if relevant)

Interview context

Expectation and second-guessing

Example:

• I think I was wrong on a previous answer so I don’t want to get it wrong again
• The information I have contradicts or doesn’t fit with what you have told me/implied, so I don’t want to say
• I saw/recall something, but several people are being interviewed and I want to avoid being contradicted by another source

Explanation:

• Interviewees may feel embarrassed/worried they have provided incorrect information; go along with interviewer (or fabricate) to avoid conflict
• Interviewees make assumptions about what the interviewers think/know

Response:

• Develop rapport and trust, highlighting the benefits of disclosed information
• Use metacognitive evaluations (confidence evaluations)
• Assure that their account is important and people can witness/observe things in different ways
• Normalise error (e.g. acknowledge that task is difficult and errors may occur)