1. Problems in Research Poor design decisions Researcher bias
Researcher effects on participants
Things participants may do regardless
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2. Poor Design Problems that stem from a badly designed study
Poor operationalisation of variables
Inadequate control of variables
Threaten the internal validity of the study
Cause reliability problems
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3. Poor Design Poor operationalisation
Insufficient care when translating unobservable psychological processes into observable behavioural ones
Can end up measuring the wrong thing
Can generate false positives or false negatives
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4. Poor Design
Reliability – the extent to which a study or measuring tool produces consistent results
Test-retest reliability
Inter-observer reliability
Reliability is maximised by (1) careful operationalisation; (2) adequate control of variables
NB: a reliable study can still be invalid
psychlotron.org.uk

5. Poor Design Inadequate controls
Extraneous variables should be held constant
Most are not a problem (random effect)
Those that have a systematic effect (e.g. affect one condition more than another) become confounding variables
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6. Researcher Bias Emphasising some things at the expense of others
Self-confirmatory bias – tendency for researchers to pay more attention to data that confirm their expectations
Reduce the need for subjective judgements by (1) careful operationalisation; (2) use of double blind
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7. Researchers & Participants
Researcher effects - behaviour of researcher can affect that of participants:
Intimidate (anxiety)
Insult (motivation)
Cue PPs to behave in particular ways
Can be reduced through standardisation of scripts and procedures
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8. Researchers & Participants
Interviewer effects – characteristics of the researcher can affect how PP relates to them; hence their responses
Gender
Social class
Age
Ethnicity…
Difficult to predict, impossible to eliminate
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9. Participants…
…are people too; people try to make sense of their situation…how they do this is not always predictable.
Attempts to please (or displease) the researcher
Management of self-presentation
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10. Participants Respond to the fact that they are being studied
Evaluation anxiety
Feelings about the study & the researcher
Effects on motivation – please the researcher or confound the results; depends on how researcher is perceived
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11. Participants
May respond to demand characteristics (cues); these can enter the research:
Through poor design e.g. allowing PPs to be aware of both conditions in an expt
Through researcher behaviour e.g. unwittingly indicating desired behaviour
Can be reduced through careful choice of design; standardisation; double blind
psychlotron.org.uk

12. Participants
Generally try to manage how they are perceived by others (we all do); can lead to:
Socially desirable responses
Other distortions of truth in order to manage impressions (how depends on who and why)
Can be reduced through anonymity, confidentiality but rarely eliminated
psychlotron.org.uk

13. General Precautions Start with the aim, not the procedure
Pay attention to choice of design, controls, operationalisation etc.
Pilot all procedures and materials
Use double blind procedures where appropriate & possible
psychlotron.org.uk