Chapter 3 Flashcards
Asymmetrical order effect
Order effect that has greater strength in one particular order of conditions and where, therefore, counterbalancing would be ineffective.
Baseline measure
Measure of what would occur if no experimental level of the independent variable were applied; how “untreated” participants perform.
Confounding variable
The variable that is uncontrolled and obscures the effect sought, varying with the independent variable in a systematic manner
Control group
The group is used as a baseline measure against which the performance of the experimental group is assessed.
Counterbalancing
Half of the participants do conditions in a particular and the other half take the conditions in the opposite order – this is done to balance possible order effects.
Dependent variables (DV)
Variables that is assumed to be directly affected by changes in the independent variable in an experiment
Experiment
Design in which an independent variables is manipulated, all other variables controlled and a dependent variable is measured for changes caused by the independent variable.
Factorial design
experiment in which more than one independent variable is manipulated.
Example: testing sleep and quiet environment for studying. 2x2 total
Independent samples (independent groups/measures; between groups/subjects)
Each condition of the independent variable is experienced by only one group of participants.
Example: Testing jumping rope vs strength training for cardio. 4 groups. Jumping for 30 and 60 minutes and strength for the same.
Related design (design)
Design in which individual scores in one condition can be paired with individual scores in other conditions (repeated measures and matched pairs) - based on the pre-test
Example: Example: Test the IQ before a memory test, and pair up participants with similar IQ.
Matched pairs (design)
Each participant in one group/condition is paired on specific variable(s) with a participant in another group/condition.
Example: Similar test and control group. Match pairs (similar) from each group. See the results.
Single participant (design)
Design in which only one participant is tested in several trials at all independent variables levels.
Example: This approach is particularly useful when studying individual cases or when dealing with clinical interventions tailored to a specific person’s needs.
Small n (design)
Design in which there is only a small number of participants, typically in clinical or counselling work but also where participants need substantial training for a highly skilled task.
Example: assess the effectiveness of a behavioural therapy intervention for children with autism spectrum disorder (ASD).
Unrelated design
design in which individual scores in one condition cannot be paired (or linked) in any way with individual scores in any other condition.
Example: Opinion polling. What’s your favourite phone brand, chocolate and shoe brand?
Extraneous variable (design)
Anything other than the independent variable that could affect the dependent variable; it may or may not have been allowed for and/or controlled.
Example: Testing students. Extraneous variable could be student motivation.
Independent variable (design)
Variable which experimenter manipulates in an experiment and which is assumed to have a direct effect on the dependent variable.
Example: Gatorade in testing if certain beverages effect if the runner gets faster
Levels (of the IV) (Design)
The different values taken by independent variable; often, the conditions of an experiment, e.g., levels of caffeine at 50mg, 100mg and 200mg in the investigation of memory recall.
Non-equivalent groups
A possible confounding variable where two or more groups in an independent samples design experiment differ on a skill or characteristic relevant to the dependent variable.
Example: testing reading skills, but picking 2 very different schools in level.
Resolve this my “matching” or “random assignment”.
Order effect
A confounding effect caused by experiencing one condition, then another, such as practice or fatigue.
Example: testing a new learning method, but instead of having A and B, they have half of A and half of B at a time, so some do not get the better learning method before the regular. To minimize differences and validate result.
Randomisation
Placebo group
Group of participants who don’t receive the critical “treatment” but everything else the experiment group receives.
Pre-test
Measure of participants before an experiment in order to balance or compare groups, or to assess change by comparison with scores after the experiment.
Randomisation
Putting stimulus items or trial types into random order for the purpose of elimination of order effects.
Example: ref order effect
Standardised (procedure)
testing or measuring behaviour with exactly the same formalised routine for all participants.
Vignettea
story, scenario or other description given to all participants but with certain details altered and this difference constitutes the independent variable.
Example: adding a political stance in picking an environmental approach.
Problems associated with these^ Experimental Designs:
Order effect
Non-equievalent stimuli
Participant variables
Non-equivalent groups
