research methods.

psychology AS.

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  • Created by: Chloe.
  • Created on: 17-05-11 16:11

Experemental measures - field, lab, natural.

FIELD - conducted in a natural environment outside the lab, but you can still manipulate the IV.

:) high ecological validity
:) demand characteristics avoided in some cases

:( low control over extraenous variables
:( ethics - lack of informed concent.

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Experemental measures - field, lab, natural.

LAB - conducted in a controlled environment in which you can manipulate the IV in order to measure the effect upon the DV.

:) high control
:) easily replicated
:) relationships can be established

:( artificial - lacks ecological validity
:( demand characteristics
:( ethics - deception, protection from harm
(psychological harm due to stressful environment)

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Experemental measures - field, lab, natural.

NATURAL - conducted in a natural environment in which the researcher does not manipulate the IV.

:) can study behaviours that would otherwise be
unethical in a lab.

:) high ecological validity.

:( low control over extraenous variables
:( ethics - deception often used and a lack of concent.

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non-experimental methods

- spontaneous behaviour in a natural setting.
- observation in a situation set up by the researcher.

:) nauralistic observations are likely to produce spontaneous behaviour so they are likely to have higher internal validity.
:) can collect data where it would otherwise be unethical for example - Tizzard and Hodges who observed childrens behaviour in an institution.
:( difficult to be objective.. what one person sees as agressive, another may not. This can be overcome by inter rater reliability and behaviour categories.
:( extraenous variables cannot be controlled in a naturalistic observation meaning there may be another reason for behavious other than what you are looking for. Therefore it lacks internal validity.

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non-experimental methods

- Ask people questions to find out information. You must be sure what you are asking and make sure questions are clear. You need to do a pilot study to make sure that it is clear. Questions can be either open or closed.

:) People do not need special training in order to conduct one. Thus making it cheaper and quicker than interviews.
:) Replicate easily and gather large amounts of info.
:) People are more likely to give info.

:( If the wording is not clear on the questionnaire this means the data collected will be difficult to analyse meaning you may not be measuring what you intend to. Therefore lacking internal validity.
:( Bias sample as only certain types of people are likely to fill it out.
:( Socially desirable answers.

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non-experimental methods.

Interviews - there are three types:
1. Non directive.. no structure.
2. Informal - list of topics.
3. Structured - every person is asked exactly the same.

:) can give rich detailed data compared with a questionnaire. You can ask participants further questions to find out why which you couldnt do with a questionnaire.

:( participants may not tell the truth. They can give socially desirable answers in an attempt to appear in a positive light.
:( time consuming and expensive compared with a questionnaire as will require trained interviewers to conduct a study.

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non-experimental methods.

Correlational Study - To see if there is a relationship attachment between two variables. No IVs,  but 2 DVs. - we measure 2 variables to see the relationship between them.
Positive correlation = as one variable increases, so does the other.
Negative correlation = as one variable increases the other decreases.

:) Good when we cant manipulate things because we just measure both variables. For example stress and illness, or looking at the effects of day care. It would be unethical to try and make this happen to someone.
:) Can get large amounts of data quickly.

:( Can't establish cause and effect. You cannot be sure that one variable causes the other. For example does day care cause children to be agressive?
:( A third variable might be involved. Having an extraenous variable would mean that it lacks ecological validity.

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VOLLUNTEER where participants self select, they choose to take part. For example putting an advert out asking people to take part.
+ :) Lots of participants compared to opportunity.
- :( Bias - only certain people will vollunteer.

RANDOM where all memebers of the intended population have an equal chance of being selected to take part. For example number picked out a hat.
+ :) Un-bias sample, therefore high population validity.
- :( Need lots of participants.
- :( TIme consuiming.

OPPORTUNITY where certain members of the population are used because they are available. For example simply using people who are there and able.
+ :) Quick and easy to get participants compared to random.
- :( High chance of bias, leading to low population validity.

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Experimental designs.

Repeated Measures.

The same participants are used in each condition. (a condition is a particular experience in an experiment that can then be compared to other experiences)

:) You compare participants with themselves - controlls individual differences.
:) Less participants needed than independant measures.

:( Attention - some participants drop out between conditions.
:( Order effects: might get better or worse  the second time they do the experiment. Therefore we should counterbalance. For example half to A then B, the other half do B then A.

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Experimental designs.

Matched Pairs.

Similar participants are used in each condition. These are seperate groups that have been matched. For example by IQ.

:) Less individual differences than independant measures.
:) No order effects.

:( Difficult and time consuming to match them.
:( Can't controll all individual differences and match them for everything!

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Experimental designs.

Independant Measures.

Different participants used in each condition.

:) No order effects.
:) Participantsd don't drop out between conditions.

:( Participant variables (individual differences) Some may be naturally better.
:( Need more participants than in repeated measures.

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