Research Methods Flashcards
Hypothesis
A precise testable statement of what the researcher predicts the outcome will be
Independent variable
What the researcher changes
Dependant variable
What the researcher measures
Alternative hypothesis
States there is a relationship between the 2 variables being studied
(Not due to chance + significant in supporting theory)
Null Hypothesis
There is no relationship between the 2 variables being studied
(Results are due to chance + not significant support)
Non directional Hypothesis
Two-tailed non-directional hypothesis predicts that the IV will have an effect on DV but direction is not specified
Directional Hypothesis
One-tailed directional hypothesis predicts nature of effect of IV on DV
How to write hypothesis
1) identify key variables
2) operationalise the variables
3) decide on direction of prediction
4) write hypothesis, short w clear and simple language
Sampling
The process of selecting a representative group from pop under study
Extraneous variables
Nuisance variables that do not vary systematically with the IV. A researcher may control some of these
Confounding variables
Change systemically with the IV so we cannot be sure if any observed change in the DV is due to the CV or the IV. CVs must be controlled
Demand characteristics
Any cue from the researcher or research situation that may reveal the aim of the study
Investigator effects
Any effect of the investigator’s behaviour on the outcome of the research (the DV)
Randomisation
The use of chance when designing investigations to control for the effects of bias
Standardisation
Using exactly the same formalised procedures for all participants in a research study
Control groups
Used for the purpose of setting a comparison
Act as a ‘baseline’ and help establish causation
Single blind
Participant doesn’t know the aims of the study so that demand characteristics are reduced
Double blind
Both researcher and participant don’t know the aims of the study to 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
Independent groups ADVANTAGES
+No order effects
Ptp only tested once so cant practice or become bored/tired. This controls an important CV
+Will not guess aim
Ptp only tested once so unlikely to guess research aims. Behaviour may be more ‘natural’
Independent groups DISADVANTAGES
-Participant variables
Ptp in the 2 groups are different, acting as EV/CV. may reduce validity of the study
-More participants
Need twice as many ptp. More time spend recruiting which is expensive
Repeated measures
- Same participants take part in all conditions of an experiment
- The order of the conditions should be counterbalanced to avoid order effects
Repeated measures ADVANTAGES
+Participants variables
The person in both characteristics has the same characteristics. Controls an important CV
+Fewer participants
Half the number of ptp is needed than in indpendant groups. Less time spent recruiting ptp
Repeated measures DISADVANTAGES
-Order effects
Ptp may do better or worse when doing a similar task twice. Reduces validity
-Participants may guess aims
Ptp may change their behaviour. May reduce validity