What is observer expectancy/bias?
An observer/rater is used to score behaviour, and the rater is biased to score participants behaviour as consistent with the hypotheses. It is a frequent problem in observational measures and scoring of free narratives
True or False: Observer Expectancy/Bias is a type of Measurement Error
True - due to taking a human to provide scores
What is the difference between observer expectancy and observer criterion shift?
Observer criterion shift is where the observer learnt to apply criteria and the criteria changed in a systematic manner with the learning, whereas observer expectancy does not involve learning
True or False: All types of blind testing avoids observer or rater expectancy confounds
False - only double blind, whereas single blind does not, as the observer/rater still knows
When do experimenter expectancy issues occur?
When the experimenter communicates to the participant what to do to support the hypotheses
What are the two major sources of experimenter expectancy?
Experimenters communications and demand characteristics
What is participant expectancy or bias?
When participants change their behaviour, not in response to the intervention or manipulations, but because of their beliefs or expectations (about the purpose of a study or about how they are supposed to behave) - which compromises the validity of the study.
What are the different kinds of participant bias?
Demand compliance, participant resistance, the Hawthorne Effect, social desirability/positive self-presentation, and placebo and nocebo effects
What is demand compliance?
A kind of participant bias where the the participant responds in accordance with demand characteristics. The hypothesis will be supported and the study confounded.
What is participant resistance?
A participant bias where the participant tries to resist what they think the experimenter wants them to do. It is usually a counter confound
What is a pre-requisite for demand compliance and resistance?
Hypothesis guessing - the participants must be able to guess what the hypothesis/aim of the study is
What is face validity?
The extent to which a test subjectively seems to capture the construct it purports to measure.
What is the Hawthorne Effect?
When the treatment group changes their behaviour not because of the treatment itself, but because they know they are being observed.
What is social desirability response?
Where participants respond in a way that portrays them in a good light, or at the very least, not in a bad light
What are some of the techniques used to circumvent social desirability response?
Guaranteeing anonymity and ballot box method
Bogus pipeline
Nominative and best friend techniques
Which techniques do not work well to mitigate the social desirability response?
Randomised response technique, group answer methods, and unmatched count technique
What is the Dunning-Kruger Effect?
A cognitive bias where people with low competence in a particular area tend to overestimate their own knowledge or ability, where highly competent individuals tend to underestimate theirs
What are the factors which explain the Dunning-Kruger effect?
Limited competence prevents people from accurately assessing their own performance and the performance of other people. High competence leads to underestimating task difficulty, leading experts to downplay their performance.
What is a placebo?
A completely ineffective substance or intervention that can cause genuine physical benefits or improvements in self-reported well-being
What is a nocebo?
A completely ineffective substance or intervention that can cause genuine worsening of a physical condition or self-reported wellbeing
How can we prevent expectancy effects?
Using procedures to disguise the purpose of the study
Using measures that are impossible to fake, or at least costly to fake
Using double blind testing
Using experimenters who do not know the hypothesis
Why is deception an ethical issue?
It undermines the participants belief in science. Loss of trust can be especially problematic in psychology - where trust in psychologists is often necessary for therapuetic interventions to be effective.
