AFP L3

eyewitness testimony

Estimator Variables: Event (ADVOCATE)- (R. v Turnbull, 1977)

•Amount of time

•Distance of witness to event (Lindsay et al., 2008)

•Visible (Wagenaar & van der Schrier, 1996)

•Obstructions (Sharps, 2010)

•Known (Bruce, 1982)

•Any reason to remember (Shapiro & Penrod, 1986)

•Time lapsed before retrieval (Shapiro & Penrod, 1986)

•Errors or material discrepancies (unsupported)

• + gun effect + stress effect

Estimator Variables: People

•Older witnesses & children show poorer accuracy (Pozzulo & Lindsay, 1998)

•Witness alcohol use leads to poorer encoding & storage (Cutler & Penrod, 1995) & poorer identification (Hilliar et al., 2010)

•Accuracy declines as the number of perpetrators increases (Fahsing et al., 2004)

•Distinctive & attractive faces more likely to be correctly identified (Brewer et al., 2005)

•Witnesses make less accurate identification of perpetrators from another race (eg. Meissner & Brigham, 2001)

•Better identification of perpetrators of similar age (Harvard et. al., 2012)

•Recognition bias for own gender (Wright & Sladden, 2003)

system variables

• interview methods and questioning style

• Line-ups (identity parades):

·Identification method used (Deffenbacher et al., 2006)

·Mode of line-up presentation (Cutler et al., 1994)

·Instructions given to the line-up witness

        (Steblay, 1997)

·Method used to select line-up foils (Wells et al., 1993)

·Blind vs. non-blind administration of a line-up (Phillips et al., 1999)

·Method of line-up presentation (simultaneous vs. sequential) (Steblay et al., 2001)

Feedback provided to witness

limitations

•Low ecological validity. Less effect in real-world? (Yuille & Cutshall, 1986)

•The misleading questions might not change the original memory.  They might just interfere with its retrieval.

•There are limits on how information can be distorted, especially if it is distinctive. Manipulations need to be fairly subtle (“passed barn”)

•Only a proportion of participants affected. People will vary on their susceptibility to the misinformation effect for various reasons:

why do people vary on their susceptibility to the misinformation effect?

•Young children (Bruck et al, 2012) and elderly adults (Loftus, 2005) are particularly susceptible.

•People with greater working memory capacity can form more coherent memories of the original event (Kerry, 2004).

•Personality factors may be relevant. Introverts more likely to have less confidence in own memories (therefore more susceptible) (Kerry, 2004).

•People who are capable of forming elaborate visual images were more likely to be influenced by misinformation (Kerry, 2004).

Gurney, Ellis & Vardon-Hynard (2016): alleyway attack study results

•More participants stated that they had witnessed a stabbing when the interviewer performed the stabbing gesture.

Also: participants in this condition also more likely to say that

–the man was carrying a weapon

–the other man was seriously injured.

Gurney, Vekaria & Howlett (2013): office CCTV study results

significant difference in mean confidence ratings between the positive n-vf and negative n-vf groups, despite participants having a similar level of accuracy across all conditions.

what does UK police PEACE interview framework stand for?

PEACE = Planning, Engage, Account, Closure, Evaluation

cognitive interview methods

–Developing Rapport + Transfer Control to witness

–Open-ended Report + memory-jogging methods:

•Context Reinstatement

•Report Everything

•Change Order* (Multiple & Varied Retrieval)

•Change Perspective* (Multiple & Varied Retrieval)

–Questioning Phase: Openàspecific

–Closure

does cognitive interviews work?

•General consensus CI superior in respect of enhancing correct recall while maintaining accuracy (Memon et al., 2010; Paulo et al., 2013)

•CI and emotional traumatic or distressing events? (Memon et al., 2010)•

•Little evidence of the CI procedure having been used at all in the vast majority (83%) of police interviews examined (Clarke & Milne, 2005)

Interviewing Child Witnesses

•Historic scepticism about child competence (but may be only witness)

•More vulnerable – cognitive & language development, suggestibility

•Open-ended questions/free recall more accurate (but less complete)

•Require more external cues to access memories

•Use of nonverbal props (dolls/toys) – only for those over 5 yrs

•Need rapport and supportive atmosphere

•Use of structured approached eg. CI  for over 7yrs, Memorandum Step-wise (Home Office, 1992), NICHD Protocol (NICHD, 2011)