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Research methods - Coggle Diagram
Research methods
types of sampling
systematic sampling:
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negative: a complete list of the population is required which takes time and effort so you may as well use random sampling.
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random sampling:
every person has an equal chance of being selected by lottery method (all being placed in a hat and names drawn)
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Volunteer sampling:
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negative: it is likely to be a bias sample as the participants may share certain traits hence, generalisation is limited.
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opportunity:
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negative: it is bias and therefore not representative of the target population meaning the findings cannot be generalised.
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Types of research:
Field study:
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negatives:
It is more difficult to control confounding variables as the changes in the DV's may not be due to the IV, but the CV.
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positives:
Natural environment, the participants are comfortable and the results can be generalised easier.
Participants are unaware they are being studied, they are more likely to behave normally and it has greater external validity.
Natural experiment:
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negative:
the event may occur only rarely, the natural experiment is a 'one off' and that limits the results that can be found
participants are not randomly allocated meaning the experimenter has no control over which participants are placed in which condition.
positive:
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greater external validity: the natural experiment involves real-life issues and the findings are more relevant
laboratory experiment:
A controlled environment where extraneous and confounding variables can be regulated. The IV is manipulated and the DV recorded.
Positives:
The extraneous variables and the confounding variables can be controlled meaning their effects on the DV can be controlled and that causes a high internal validity.
It can be easily replicated as it is in a lab and it is standardised, it can also be repeated which gives it a high validity.
Negatives:
It may lack generalisation as the participants are aware they are being studied, causing a low external validity.
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quasi experiment:
positive:
high control of the experiment as they are easily replicated and the confounding/extraneous variables can be controlled
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negative:
casual relationships are not demonstrated meaning the researcher doesn't manipulate/control the IV and then we cannot say if any change of the DV was because of the IV
the participants are not randomly allocated so the participant variables may change in the DV acting as the CV
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research issues:
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 CV or the IV. They must be controlled.
demand characteristics: any cue from the researcher or the research situation which may reveal the aim of the study and people consequently change how they act.
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experimental designs:
Independent groups
One group does condition A and one group condition B.
They should be randomly allocated to experimental groups.
Positives:
No order effects. The participants are only tested once so the results can't be practiced and participants can't become bored/tired
The participants won't guess the aim of the experiment. They are only tested once so they will be unlikely to guess the research aims, therefore behaviour may be more 'natural'.
Negatives:
The participant variables, the participants in the teo groups are different, hence acting as an EV and a CV. Therefore, reducing the validity.
More participants, you need twice as many participants as your repeating measures for the same data which is more expensive and time taking
Repeated measures:
Positive:
the participant variables as the person in both conditions has the same characteristics. This controls an important CV.
Fewer participants meaning as half the number of participants is needed in the independent groups. Hence, less time is spent recruiting people.
Negatives:
there is the order effects being a problem. The participants may do better/worse when doing a similar task twice and that reduces the validity of the results.
The participants may guess the aims of the experiment and consequently, change their behaviour which reduces the validity of the experiment.
same participants take part in all conditions of the experiments. The order of the conditions should be counterbalanced to avoid order effects.
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