Research Methods Flashcards
Aim
A general expression of what the researcher intends to investigate
Hypothesis
A statement of what the experimenter believes to be true / expects to happen
Operationalised
Clearly defined and measurable
Directional hypothesis (one tail)
States whether changes are greater or lesser, positive or negative
Non-directional hypothesis (two tailed)
Doesn’t state direction just states that there is a difference, correlation, association.
Experimental method
A researcher causes the independent variable to vary and records the effect of the IV on the dependent variable
There are different levels of the IV
Extraneous variables
‘Nuisance’ variables that do not vary systematically with the IV. A researcher may control some of these.
Confounding variables
Change systematically with the IV so we cannot be sure if any observed change in the DV is due to the confounding variable or the IV. CVs must be controlled.
Demand characteristics
Refers to any hint from the researcher or research situation that may reveal the aim of the study
Investigator effects
Any effect of the investigators behaviour on the outcome of the research (the DV)
Randomisation
The use of chance to control bias within investigations
Standardisation
Using exactly the same formalised procedures for all participants in a research study
Control groups
Control groups are used for the purpose of setting a comparison
Single blind
A participant doesn’t know the aims of the study - demand characteristics are reduced
Double blind
Both participant and researcher don’t know the aims of the study the reduce demand characteristics and investigator effects
Independent groups
One group do condition A and a second group do condition B. Participants should be randomly allocated to experimental groups.
Advantages of independent groups
No order effects - participants only tested once so won’t get bored/tired - controls an important confounding variable
Will not guess aim - participants only tested once so less likely to guess research aim - behaviour may be more normal
Disadvantages of independent groups
Participant variables - the participants in each group are different - acts as an extraneous or confounding variable - reduces validity
More participants - need twice as many people - more time spent recruiting - more expensive
Repeated measures
Some participants take part in all conditions of an experiment. The order of conditions should be counterbalanced to avoid order effects.
Advantages of repeated measures
Participant variables - the person in both characteristics has the same characteristics- controls an important confounding variable
Fewer participants - half the number of participants is needed - less time spent recruiting participants
Disadvantages of repeated measures
Participants may guess aims - participants may change their behaviour - may reduce validity of results
Order effects are a problem - participants may do better or worse when performing a similar task twice - reduces validity of results
Matched pairs
Two groups of participants are used but they are also related to each other by being paired on participant variables (characteristics) that matter for the experiment (e.g. Age, gender)
Advantages of matched pairs
Participant variables - participants are matched on a variable (characteristic) that is relevant to the experiment - enhances the validity of results
No order effects - participants only tested once so no boredom or fatigue - improves validity
Disadvantages of matched pairs
Matching is not perfect - matching is time consuming and can’t control all relevant variables - may not address participant variables
More participants - need twice as many participants - time consuming and expensive
