Experimental design Flashcards
What is the ceiling effect?
Task is too easy, scores are all high
What is the floor effect?
Task is too difficult, all scores very low
Experimental design
Process of constructing experiments and the resulting of the structure
External validity
The extent to which a research finding fan be generalised to other situations
Operationalisation
The process of deciding how to manipulate and/or measure independent and dependent variables
Between-subjects manipulation
Systematic change to an independent variable where different participants are exposed to different levels of that variable by the experimenter
Manipulation check
A dependent measure that checks that manipulation of the independent variable has been successful
Within-subject manipulation
Systematic change to na independent variable where the same participants are exposed to different levels of that variable by the experimenter
Relevance-sensitivity trade-off
The principle that the more relevant a dependent variable is to the issue in which a researcher is interested, the less sensitive it may be to variation in the independent variable
What percentage of research papers in psych used undergrad first years as their participants?
80%
Matching
Process of attempting to remove systematic differences between experimental groups on variables not of primary interest but considered likely to produce differences in a dependent variable
Naive empiricism
The process of directly generalising research findings to other settings and samples, without basing that generalisation on a theory or explanation of the research findings
History effects
Threats to internal validity posed by events occurring between two experimental observations. These events can be of both major import or relatively mundane
Instrumentation effects
Threats to internal validity arising from changes in dependent variables and materials used to record them
Maturation effects
Threats to internal validity posed by the capacity for the passage of time to produce changes in the participants between two experimental observations
Mortality effects
Threats to internal validity created by the selective withdrawal of participants from an experiment
Order effects
Experimental effects that result from sequencing of experimental treatments or the completion of dependent measures
Post-test
An observation made after an experimental treatment
Practice effects
A special case of maturation effects where performance on a post test is improved as a result of the practice gained from performing pre test
Pre-test
An observation made before an experimental treatment
Reactivity
Change in dependent variables caused by obtaining responses on those dependent variables
Regression to the mean
The tendency for observations and responses that are extreme on one measure to be closer to the mean on another measure. If this problem is not recognised, it constitutes a threat to internal validity
selection effects
Threats to internal validity posed by assigning participants to conditions on a non-random bias
Testing effects
threats to internal validity that arise when response on one dependent measure affect responses on another
Counterbalancing
Systematic variation in the order in which participants respond to dependent measures or receive treatments.
Fatigue effects
A case of maturation effects where performance on a post test deteriorates as a result of boredom or tiredness from a pre test
Hawthorne effect
A threat to internal validity posed by peoples awareness that they are participating in research. The findings arise from the awareness that research is being done. A case of reactivity
Blind experimental
A control for experimenter bias by making the experimenter unaware of the condition of which participants have been assigned
Concealment
A research strategy similar to deception the involves giving participants limited information about a study
Cover story
Information about the supposed purpose of a piece of research
Deception
the strategy of misleading participants in order to conceal the purpose of the study and avoid reactivity.
Demand characteristics
Cues that convey an experimental hypothesis to participants
Experimenter bias
a threat to external validity that arises when experimenters construct or conduct an experiment in such a way that it unfairly tests an experimental hypothesis
Interaction
A situation where the effect of one IV depends on the level of another
What is statistical conclusion validity
The degree to which conclusions about the relationship among variables based on the data are correct
What is construct validity
Adequate manipulations of IV and appropriate measures of DV
What is ecological validity
The extent to which results can be generalised to other environments
What is naive empiricism
To not validate the theory and apply the theory to the real world
What is a carryover effect
One sequence of conditions produces different results than another sequence
What is complete counterbalancing
Do you every possible sequence in the conditions
What is partial counterbalancing
Do a couple of possible combinations of conditions
What an acquiescence tendency
Participant changing behaviour in order to please experimenter and do what is expected
what is blocked random assignment?
Guarantees equal number of participants per group
Ensures that each condition has participant in it before any other condition is repeated – each block contains all conditions in a randomised order
