ao3

strength - lab experiment , systematic procedures

lab experiments

High Control in Lab Setting

• Variables tightly controlled

• Stronger cause‑and‑effect conclusions Clear Manipulation of IV

• Verbs in critical question (e.g., smashed vs hit) = manipulated IV

• DV = speed estimates → measurable impact

Increased Internal Validity

• Extraneous variables controlled

• More accurate measurement of the leading question effect

• Supports conclusion: question wording distorts memory

systematic procedures

High Internal Reliability

• Standardised procedure: same video, same viewing time

• Random allocation to verb conditions (e.g., smashed, contacted)

• All participants treated the same

Consistent & Replicable Findings

• Controls ensure IV (verb) caused differences in speed estimates

• Scientific, objective method → fewer confounding variables

Trustworthy Evidence

• High standardisation = easy replication

• Boosts confidence in the reliability of the result

methodology and procedures strenght - social

Positive Impact on Society

• Research has improved accuracy of eyewitness testimony

Cognitive Interview Development

• Avoids leading questions

• Witness-led recall: own words, own pace

• Reduces memory contamination

Benefits to Justice System

• Helps prevent wrongful convictions

• Shows psychology’s real-world value

weaknesses of methodology and procedures - lack of ecological validity , low population validity

Demand Characteristics

• Participants may guess the aim and change behaviour

• Some admitted giving speed estimates they thought researchers wanted

• “Didn’t want to ruin the experiment” → helpful bias

Threat to Internal Validity

• Responses may reflect expectations, not actual memory distortion

• Hard to tell if verb manipulation or participant behaviour caused changes

lack ecological validity

Artificial Lab Setting

• Participants watched short video clips

• Knew it was a study → lacked realism and emotional intensity

Low Real-Life Stress

• Real eyewitnesses face unpredictable, emotional events

• Lab lacks urgency, fear, and consequence

Foster et al. (1994)

• Accuracy was higher when participants believed the event was real

• Suggests real-life memory may be more reliable than Loftus & Palmer imply Generalisability Issue

• Findings may not apply to real-world eyewitnesses

• Limits external validity

issues with the sample - low population validity, including source monitoring

Student Sample

• Used American university students

• Limits generalisability to wider population

Age & Experience Differences

• Students differ in age, life experience, and susceptibility to misleading info

• Real eyewitnesses vary more in background

Schacter et al. (1991)

• Older adults struggle more with source monitoring

• More vulnerable to misleading info than younger adults

External Validity

• ConcernFindings may not apply to real eyewitnesses

• Reduces generalisability

ethical impication - lack of valid conset , dceoption , protextion

Lack of Valid Consent

• True aims (e.g., leading questions) not revealed

• Participants unaware of manipulation

Deception

• May alter behaviour → participants try to resist influence

• Threatens internal and ecological validity

Justification via Cost–Benefit

• Deception was mild and helped reduce demand characteristics

• Research improved understanding of eyewitness reliability

• Influenced legal practices → ethical costs arguably justifie

Use of Video Clips

• Participants watched video clips, not real accidents

• Lower emotional impact → reduced realism

Ecological Validity Concern

• Real eyewitnesses experience stress/shock, which affects memory

• Lab lacks emotional intensity

Ethical Constraints

• Showing real accidents = psychological harm

• Would breach ethical guidelines

Ethical–Scientific Balance

• Video clips ensured participant safety

• Still allowed investigation of leading questions

• Study balanced ethical protection with scientific aims, though realism was reduced