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
