Bias Flashcards

1
Q

What is the connection between CAI and bias?

A
  • importance of a transparent and logical process in both assessment and interpretation
  • forensic science is context dependent but information conveyed incorrectly may bias opinion
  • CAI requires choices to be made and unless conducted correctly these may introduce bias
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2
Q

What are the four key requirements to act with in the Forensic Science Regulator’s Codes of Practice and Conduct for Forensic Science Providers and Practitioners?

A
  • honesty
  • integrity
  • objectivity
  • impartiality
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3
Q

What are the three categories of cognitive bias?

A
  1. expectation
  2. confirmation
  3. anchoring effects or focalism
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4
Q

What is expectation bias?

A
  • also known as experimenter’s bias
  • where the expectation of what an individual will find affects what is actually found
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5
Q

What is confirmation bias?

A
  • whereby people test hypotheses by looking for confirming evidence rather than for potentially conflicting evidence
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6
Q

What is anchoring effects or focalism?

A

occurs when an individual relies too heavily on an intial piece of information when making subsequent judgements, which are then interpreted on the basis of the anchor

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7
Q

What are three forms of bais’s?

A
  • overconfidence - too confident and you take greater risks
  • recency - the tendency to weigh the latest information more heavily than older data
  • salience - our tendency to focus on the most easily recognisable features of the situation or concept
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8
Q

What is anchoring bias?

A

being over reliant on the first piece of information they hear

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9
Q

What is availability heuristic?

A

people who overestimate the importance of information that is available to them

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10
Q

What is the bandwagon effect?

A

the probability of one person adopting a belief increases based on the number of people who hold that belief

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11
Q

What is blind spot bias?

A

failing to recognise your own cognitive biases is a bias in itself

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12
Q

What is choice supportive bias?

A

when one chooses something which we tend to feel positive about

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13
Q

What is clustering illusion?

A

the tendency to see patterns in random events

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14
Q

What is confirmation bias?

A

when we tend to listen only to information that confirms our preconceptions

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15
Q

What is conservativism bias?

A

where people favour prior evidence over new evidence or information that has emerged

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16
Q

What is information bias?

A

the tendency to seek information when it does not affect action

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17
Q

What is the ostrich effect?

A

the decision to ignore a dangerous or negative information by buring one’s head in the sand

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18
Q

What is outcome bias?

A

judging decisions are based on the outcome rather than how exactly the decision was made

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19
Q

What is selective perception?

A

allowing our expectations to influence how we perceive events

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20
Q

What is survivorship bias?

A

an error that comes from focusing only on surviving examples causing us to misjudge a situation

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21
Q

What does the Criminal Procedure Rules say about an experts duty to the court?

A
  • an expert must help the court to achieve the overriding objecting by giving an opinion that is objective and unbiased and within the experts area of expertise
  • this duty overrides any obligation to the person from whom the expert receives instructions or by whom the expert is paid
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22
Q

What is the role of the forensic expert?

A
  • to evaluate findings and results in the context of relevant circumstances
  • the opinion should be balanced, robust, logical and transparent
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23
Q

What is contextual bias?

A

where someone has other information aside from that being considered which influences (either consciously or subconsciously) the outcome of the consideration

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24
Q

What are role effects?

A
  • where scientists identify themselves within adversarial judicial systems as part of either the prosecution or defence teams
  • this may introduce subconscious bias that can influence decisions
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25
Q

What is motivational bias?

A
  • occurs where motivational influence on decision makiing, results in information consistent with a favoured conclusion tending to be subject to a lower level of scrutiny than information that may support a less favoured outcome
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26
Q

What are reconstructive effects?

A
  • occur when people rely on memory rather than taking contemporaneous notes
  • people tend to fill in gaps with what they believe should have happened
  • may be influenced by protocol requirements when recalling events
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27
Q

When are the risks of bias lower?

A
  • when results are clear and unambigious
  • a methodical approach with defined standards build on principles that have ben tested and validated
  • practitioners are well trained, experienced and continuously meet acceptable standards
  • full independent reinterpretation is done
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28
Q

When are the risks of bias greater?

A
  • when the approach is unresearched and personal to the practitioner
  • when results are complex, of poor quality and there is an increased reliance on subjective opinion
  • practitioners are inexperienced, unmonitored and left to adopt their own approach
  • checking is conducted collaboratively or not at all
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29
Q

What is debias?

A

the reduction or elimination of the impact of bias in decision making and problem solving

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30
Q

What is photogrammetry?

A

the practice of obtaining reliable information about physical objects through the processes of recording, measuring and interpretating photographic images

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31
Q

What is psychological contamination?

A

exposure to other information that is irrelevant to the assessment but that introduces sub consious bias into the findings

32
Q

What are the threats to impartiality?

A
  • being the sole reviewer
  • being over-familiar
  • having organisational and management structures that could be perceived to reward bias where a culter of performance measurment and time pressures could pressurise examiners into biasing decisions
33
Q

How to make sure people are not susceptible to psychological and cognitive influences?

A
  • proficiency-testing
  • blind trials - can be time consuming tho
  • undertake a mixed programme of declared and undeclared trials
34
Q

How to avoid reconstructive effects?

A
  • contemporaneous notes
  • during collection and processing
35
Q

What is a brief outline of forensic processes that a lab follows?

A
  • define requirement
  • develop examination strategy
  • agree examination strategy with client
  • carry out analyses
  • review the quality and content of results
  • compare results with references
  • evaluate and interpret findings
  • second expert verifies
  • communicate findings
36
Q

What are the ways to reduce the risk of cognitive bias in evaluative mode?

A
  • go through a formal process of pre-assing the expected probabilities for a realistic range of outcomes in as many or as few categories as is sensible for the examination
  • record their opinions
37
Q

What type of bias does the LR decrease?

A

confirmation

38
Q

What are the factors that police must take into consideration when attending a scene?

A
  • preserving the scene
  • securing evidence
  • the speed of response
  • the proportionate use of resources based on the seriousness of the crime
  • all are overriden by the preservation of life tho
39
Q

R v Pickering

A
  • convicted for sexual assult on a girl under the age of 13
  • none of the DNA results were suitable for statistical analysis as there must have been at least one other unknown person who contributed to the mixed profile
  • no likelihood ratios were able to be made
  • presence of amylase was strong supportive evidence for the Hp
40
Q

Why has there been an increasing risk of cognitive contamination in DNA evidence?

A
  • stochastic effects is increasing
  • conditions in which subjective opinion tends to be relied on are more commonly encountered
41
Q

Dlugosz case 2011

A
  • convicted of burglary robber and manslaughter
  • could not quantify the level of support from the DNA samples found on chisels because it was a mixed profile
  • since then if you cannot statistically evaluate the DNA evidence it will be ruled inadmissible
  • may have been prejudiced (biased) by his previous convictions
42
Q

What are some mitigation strategies for DNA samples?

A
  • prior interpretation of case sample result before reference result is revealed
  • noting the suitability in include or exclude
  • assessment of the number of contributors
  • level of representation of contributors
  • potential for stochastic effects
  • identification of likely/unlikely genotype combinations that might explain the mixture
43
Q

What is recommended for DNA profile interpretation in all circumstances?

A
  • full checking - repeat interpretation by an experienced and competent colleague including prior interpretations of the case sample result before the reference
  • the check should be conducted independent of and uninfluenced - use original unmodified hard copy or electronic results
44
Q

How to make the correct selection of case stains/samples

A
  • multiple analyses to asses stochastic effects in low template samples
  • replication should be applied whenever a poor quality profile is to be relied on
    *
45
Q

What do you employ when there is no option for objective evaluation?

A

quantitative and subjective-based approaches
* validated
* demonstrates robustness of resultant conclusions and opinions

46
Q

What were the findings from the scottish police services authority?

A
  • improved note taking
  • no prior knowledge or access to case-related information
  • blind verification process
  • removal of any context information or related communication documentation
  • training programmes to explore cognitive bias
47
Q

What does ACE-V stand for?

A
  1. analysis
  2. comparison
  3. evaluation
  4. verification
48
Q

When is ACE-V used?

A

fingerprint comparison

49
Q

What does ACE-V mean when analysing a print?

A
  • A: is the mark of suffcient quality
  • C: can we include or exclude
  • E: identified or not
  • V: the need for independent second checking
50
Q

What three things can the risk of inherent in the fingerprint examination process be categorised as?

A
  • contextual bias
  • confirmation bias
  • cultural bias
51
Q

How is there contextural bias in fingerprints?

A
  • nature and details of the crime (background info)
  • association with or personal knowledge of victim
  • status of person in custody
  • previous criminal activity of suspects
  • location of crime
  • media or public interest
  • personal morals
  • time pressure
52
Q

Where can there be confirmation bias in fingerprint evidence?

A
  • police and prosecution hoping it will solve the crime
  • a personal moral ode to do the right thing
  • having prior knowledge of the previous examiners findings and conclusions
53
Q

Where could there be cultural bias in fingerprint evidence?

A
  • strict hierachical structures based on time served rather than competence
  • over confidence in individual or organisation
  • lack of interaction with peers or exposure to alternative methods of working
  • lack of acceptance of the potential for errors or effective root cause analysis of errors
54
Q

Where are some examples of cognitive risks from the scottish fingerprint enquiry?

Case studies

A
  • Brandon Mayfield - resulted in a procedure review
  • Shirley McKie
54
Q

What cases do blind verifications take place?

A
  • those with single mark conclusions
  • circumstances where there are conflicts between examiners
  • circumstances where there are conflicts on decisions of value or no value
54
Q

What is a blind verification?

A

the independent application of ACE by another qualified examiner who does not know the conclusions of the primary examiner

55
Q

What is the generic process for mark evidence?

A
  1. examine the mark
  2. use recovery and enhancement techniques as required
  3. generate the control item
  4. make test marks if required in the appropriate manner
  5. undertake a comparison using appropriate methods
  6. interpret and evaluate findings
  7. verify the results
  8. describe findings in a statement or report
  9. might have to go to court to give oral testimony
56
Q

What is mark comparison like?

A
  • human operator, no instrumental analysis
  • methods are usually side by side comparisons or overlay
  • subjective assessment
57
Q

What are some mitigation strategies for mark evidence?

A
  • CAI, comparison of expected, pre-assessed outcomes of appropriate hypotheses with actual results
  • full disclosure of all data used in the evaluation
  • blind checker
  • critical findings checked by a second authorised examiner
  • validation testing
  • ongoing monitoring of the competence of practitioners using proficiency testing - quality checks
  • training and education in bias
58
Q

What is the general process for all trace evidence?

A

comparison of crime material with one or more known/reference samples

59
Q

What are some mitigation strategies for trace evidence?

A
  • independent checking - where only subjective observational assessments of a match are possible
  • independent chekcing of analytical results
  • use a statistical approach for evaluation
  • CAI - robust and documented comparison of expected and pre-assessed outcomes with actual results under appropriate competing hypotheses
  • training
  • quality assurance trials
60
Q

What are the 5 levels of taxonomy for linear sequential unmasking?

A
  1. the trace evidence
  2. reference materials
  3. case information - managed by case managers
  4. base rate expectations that arise from their experience
  5. organisational and cultural factors
61
Q

How can reference samples cause bias?

A

analysts interpretation could be influenced by knowing the characteristics of the reference sample

62
Q

What is linear sequential unmasking?

A

working from the evidence to the suspect rather than from the suspect to the evidence
* does not prevent exposure to biasing relevant info
* does manate that this info is presented as late as possible in the examination process and only when it is necessary
* first examine and document the trace evidence from the crime scene (level 1) before being exposed to the reference material (level 2)

63
Q

What factors effect decision making unconsciously?

A
  1. case evidence
  2. reference materials
  3. irrelevant case info
  4. base rate expectations
  5. organisational factors
  6. training and motivation
  7. cognitive architecture and the brain
64
Q

What is expected frequency bias?

A

being accustomed to a particular result occuring at a certain rate and then expecting it to keep occuring at the same rate

65
Q

In summary what are ways to mitigate bias in forensic investigation?

A
  • removing irrelevant contextual info from samples prior to running tests - case management
  • minimising bias in expected outcomes - blind verification
66
Q

Introduced to prevent contextual bias by protecting examiners from task irrelevant information?

A

Case managers

67
Q

Synonymous with base rate, a factor that makes unconsiously effect decision-making

A

background rate

68
Q

Where the DNA scientist is required to make their own supposition about the appropriate defence hypothesis?

A

Proxy proposition

69
Q

Refers to a property of being well described by random probability distribution?

A

Stochastic

70
Q

What type of bias is referring to subconscious influence of prior beliefs?

A

Cognitive

71
Q

Type of bias associated with extraneous information, influencing forensic judgement

A

Contextual

72
Q

When we allow the anticipated results to influence our interpretation of the evidence

A

Expectation bias

73
Q

What are some cultural influences that can impact the decision-making process from the Scottish Fingerprint Enquiry?

A
  • over confidence
  • lack of exposure to alternative methods
  • lack of acceptance of the potential errors or effective root cause analysis of errors
74
Q

What was the case of Shirely McKie 1999?

A
  • she was an investigating officer for a murder
  • it was said that her fingerprint was found
  • misidentification of fingerprint
75
Q

What was the case of Brandon Mayfield 2006?

A
  • misidentification of fingerprint
  • ignored critical differences in the prints
  • due to the unusual level of similarity, they were less focused on information which might exonerate Mayfield
  • FBI introduced a system of blind verification due to this