Key Words Flashcards
(110 cards)
Experimental method
Involves the manipulation of an independent variable (IV) to measure the effect on the dependent variable (DV). Experiments may be laboratory, field, natural or quasi
Aim
A general statement of what the researcher intends to investigate, the purpose of the study
Hypothesis
A clear, precise, testable statement that states the relationship between the variables to be investigated. Stated at the outset of any study
Directional hypothesis
States the direction of the difference or relationship
Non-directional hypothesis
Does not state the direction of the difference or relationship
Variables
Any ‘thing’ that can vary or change within an investigation. Variables are generally used in experiments to determine if changes in one thing result in changes to another
Independent variable (IV)
Some aspect of the experimental situation that is manipulated by the researcher - or changes naturally - so the effect on the DV can be measured
Dependent variable (DV)
The variable that is measured by the researcher. Any effect on the DV should be caused by the change in the IV
Operationalisation
Clearly defining variables in terms of how they can be measured
Extraneous variable (EV)
Any variable other than the independent variable (IV), that may affect the dependent variable (DV) if it is not controlled. EV’s are essentially nuisance variables that do not vary systematically with the IV
Confounding variables
A kind of EV but the key feature is that a confounding variable varies systematically with the IV. Therefore we can’t tell if any change in the DV is due to the IV or the confounding variable
Demand characteristics
Any cue from the researcher or from the research situation that may be interpreted by participants as revealing the purpose of an investigation. This may lead to a participant changing their behaviour within the research situation.
Investigator effects
Any effect on the investigator’s behaviour (conscious or unconscious) on the research outcome (the DV). This may include everything from the design of the study to the selection of, and interaction with, participants during the research process
Randomisation
The use of chance methods to control for the effects of bias when designing materials and deciding the order of experimental conditions
Standardisation
Using exactly the same formalised procedures and instructions for all participants in a research study
Experimental design
The different ways in which participants can be organised in relation to the experimental conditions
Independent groups design
participants are allocated to different groups where each group represents one experimental condition
Repeated measures
All participants take part in all conditions of the experiment
Matched pairs design
Pairs of participants are first matched on some variable(s) that may affect the dependent variable. Then one member of the pair is assigned to Condition A and the other to Condition B
Random allocation
An attempt to control for participant variables in an independent groups design which ensures that each participant has the same chance of being in one condition as any other
Counterbalancing
An attempt to control for the effects of order in a repeated measures design: half the participants experience the conditions in one order, and the other half in the opposite order
Laboratory (lab) experiment
An experiment that takes place in a controlled environment within which the researcher manipulates the IV and records the effect on the DV, whilst maintaining strict control of extraneous variables
Field experiment
An experiment that takes place in a natural setting within which the researcher manipulates the IV and records the effect on the DV
Natural experiment
An experiment where the change in the IV is not brought about by the researcher but would have happened even if the researcher had not been there. The researcher records the effect on a DV they have decided on