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
Matched pairs
Two groups of participants are used but they are also related to each other by being paired on ptp variables that matter for the experiment
Matched pairs ADVANTAGES
+Participant variables
Ptp matched on a variable that is variable. Enhances validity
+No order effects
Ptp only tested once so no practice or fatigue effects. Enhances validity
Matched pairs DISADVANTAGES
-Matching pairs is not perfect
Matching is time-consuming and can’t control all relevant effects. May not address ptp variables
-More participants
Need twice as many ptp as repeated measures for same data. More time spent recruiting which is expensive
Laboratory experiment
- A controlled environment where extraneous and confounding variables can be regulated
- Participants go to researcher
- The IV is manipulated and the effect on the DV is recorded
Laboratory experiment ADVANTAGES
+EVs and CVs can be controlled
This means the effect of EVs and CVs on the DV can be minimised. Cause and effect between the IV and DV can be demonstrated (high internal validity)
+Can be easily replicated
Due to standardised procedure, experiment can be repeated. If the results are the same this confirms their validity
Laboratory experiment DISADVANTAGES
-May lack generalisability
The controlled lab environment may be slightly artificial and ptp are ware of being studied. SO behaviour may nt be ‘natural’ and cant be generalised to everyday life (low external validity)
-Demand characteristics possibility
Cues in the experimental situation that invite a particular response from ptp. Results may be affected by these cues rather than effect of IV
Field experiment
- A natural setting
- The research we goes to participants
- The IV is manipulated and the effect on the DV is recorded
Filed experiment ADVANTAGES
+More natural environment
Ptp more comfortable in their own environment. Results may be more generalisable to everyday
+Participants unaware of being studied
They are more likely to behave as they normally do so the findings can be generalised. greater external validity
Field experiment DISADVANTAGES
-More difficult to control CVs
Observed changes in the DV may not be due to the IV, but to the CVs instead. More difficult to establish to establish cause and effect than in the lab
-There ate ethical issues
Ptp may not have given informed consent. This is an invasion of privacy, which raises ethical issues
Natural experiment
- IV is not manipulated. IV would have varied even if the experimenter wasn’t interested
- DV may be naturally occurring (e.g. exam results) or measured by the experimenter
Natural experiment ADVANTAGES
+May be only ethical option
It may be unethical to manipulate IV, e.g. studying the effects of institutionalisation on children. Natural experiment may be only causal way research that can be done for such topics
+Greater external validity
Natural experiments involve real-life issues, such as the effect of a natural disaster on stress levels. Findings are more relevant to experiences
Natural experiment DISADVANTAGES
-The natural event may only occur rarely
Many natural events are ‘one-offs’ which reduces opportunity for research. May limit scope for generalising findings
-Participants are not randomly allocated
Th experimenter has no control over which ptp are placed in which condition as the IV is pre-existing. May result in CVs that aren’t controlled, e.g. Romanian orphans adopted early may be the friendlier ones
Quasi-experiment
- IV is based on a pre-existing difference between people, e.g. age or gender. No one has manipulated this variable, it simply exists
- DV may be naturally occurring (e.g. exam results) or may be measured by the experimenter
Quasi-experiment ADVANTAGES
+Often high control
Often carried out under controlled conditions and therefore shares some of the strengths of lab experiments. Means increased confidence about drawing causal conclusions
+Comparisons can be made between people
In a quasi-experiment, the IV is a difference between people, e.g. people with and with autism. Means that comparisons between different types of people can be made
Quasi-experiment DISADVANTAGES
-Participants are not randomly allocated
The experimenter has no control over which ptp are placed in which condition as the IV is pre-existing. Ptp variables may have caused the change i the DV acting as a CV
-Causal relationships not demonstrated
The researcher does not manipulate/ control the IV. We can’t say for certain that any change in the DV was due to the IV
