Psychology as level unit 1

Laboratory experiment:  conducted in a contrived setting that isnt the pps natural environment.

Field experiment: experiments where the IV is manipulated in a natural setting e.g. where people live.

Natural experiment: studies in which a naturally occuring IV is investigated (the IV is not manipulated by experimenter) 

• A correlation is a relationship between 2 variables.
• A positive correlation is when one variable increases so does the other.
• A negative correlation is when one variable increases the other decreases.
• A zero correlation is when there is no relationship between 2 variables
• A curvilinear correlation is when the relationship is not linear but curved but there is still a predictable relationship.

There are 2 types of observation:

• A naturalistic observation: behaviour studied in a natural situation where everything has been left as it is normally.
• A controlled observation: some variables are controlled by the researcher. Pps are likely to know they are being studied & it may be conducted in a lab.

There are 2 types of observational techniques:

• Structured observations: the researcher uses various ''systems'' to organise observations (e.g. sampling procedures).
• Unstructured observations: the research records all relevant behaviour but has no system. The behaviour to be studied is largely unpredictable. Problems with this method: too much to record, only most eye catching behaviour to be recorded.

Definition: The extent to which the findings can be applied to real life as a consequence of either internal or external validity.

There are 2 types of validity:

• Internal validity: an experiment is internally valid if the observed effect can be atributed to the experimental manipulation rather than to something else. E.g. pps may be acting according to what they think is expected of them rather than there indinations (demand characteristics).
• External validity: The extent to which the findings can be generalised to other settings (ecological validity) other people (population validity) and over time.

Defintion: The extent to which a method of measuremnt or test procedures consisten findings. (Think reliable = repeatable)

There are 2 types of reliability:

• Internal reliability: How consistenly a method measures within itself.
• External reliability: The extent to which a measure varies from one use to another.
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• Deception: About the ture aims of the study.
• Psychological harm: Sensitive topics could cause distress.
• Privacy: Sensitive topics could invade a persons privacy.
• Confidentiality: Names & personal details shouldnt be revealed without permission. No personal data may be stored.

Case study: A case study is an in depth study of one person. Nearly every aspect of the subjects life and history is analysed to seek patterns and causes for behaviour. The hope is that learning gained from studying one case can be generalized to many others.

+ Provide in depth information about an area which it would be unethical to recreate for study.

- Case studies tend to be highly subjesctive and ir is difficult to generalise results to a larger population.

- Cant make before and after comparisons.

Experiments also need to have two hypotheses, the null hypothesis and the alternative or experimental hypothesis.

Experimental/ alternative hypotheses can be directional or non directional.

Different pps are used in each condition.

Advantages:

• No pps are lost between trials.
• There are no problems of order effects.
• It can be used when a repeated measures design is inappripriate.

Disadvantages:

• You need more pps than you do in others.
• There may be important individual differences between pps to start with. They should be random.

Two separate groups of people are used who are matched on a 1 to 1 basis on important variables, such as age or sex.

Advantages:

• It controls for some indvidual differences between pps.
• Can be used when a repeated measures design is inappropriate.

Disadvantages:

• You need more pps than you do in others.
• It is quite difficult to match pps in pairs, you need a large lot of pps.

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The same group of people are used in each of the 2 conditions.

Advantages:

• It controls for all indvidual differences.
• It requires fewer pps.

Disadvantages:

• There are problems with order effects.
• Pps are likely to guess the puropose of the study, which will cause problems with demand characteristics.
• It cannot be used in studies in which pps in one condition affects the response in the other.

Variables: Things which vary or change.

• Independent variables: (IV) ~ the aspect that the experimenter manipulates.
• Dependent variables: (DV) ~ the aspect that the experimenter measures or observes.
• Operationalise the variables: ~ to write them in a way which makes them testable or measureable.

Example.

• Aim: Do girls watch more TV than boys?
• IV: If pps are male or female.
• DV: How much TV they watch.
• Operationalised DV: Number of hours spent watching TV per night?

A pilot study is a dry run of your procedure. You find someone who could be one of your pps and go through your procedure in order to check whether your instructions and questions make sense. You can then make adjustments before you start collecting data you will use as your findings.

An extraneous variable is anything which is not the independent variable which might affect the dependent variable.

Questions are use throughout studies to collect data.

Strenghts:

+ Can be given to a large sample of people.

+ Pps can asnwer the questionnaire without the need for the researcher to be present, so reducing experimenter bias.

+ Compared with interviews they are easy to use, the researcher doesnt need any special training to use them.

How to deal with it.

Pps are asked to formally indicate their agreement to participate & this should be based on comprehensive information concerning the nature & purpose of the researcher & their role in it. An alternative is to gain ''presumptive consent'': by asking a similar group of people if they feel the study is acceptable...if they agree we can presume the pps will feel the same. Reasearchers can also offer the right to withdraw.

Limitations.

1, The info may invalidate the study if it explains the aim.

2, No guarantee pps really undertsand what theyve let themselves in for!

3, Problem with presumptive consent: what people expect they wont mind can be different from actually experiencing it.

How to deal with it.

The need for deception should be approved by an ethics committee, weighing up costs against benefits. Pps should be fully debreifed after the study & offered the opportunity to withhold their data.

Limitations.

1, Cost benefits are flawed: true costs arent always apparent until afterwards.

2, Debreifing cant turn clock back: pps may still have lowered slef esteem.

How to deal with it.

Pps should be informed at the beginning of a study that they have the right to withdraw.

Limitations.

1, Pps may feel they shouldnt withdraw because it will spoil the study.

2, If pps are paid they may feel they cant withdraw.

How to deal with it.

Avoid any risks greater than everyday life. Stop the study!

Limitations.

1, Researchers arent always able to accurately predict the risks of taking part in a study.

How to deal with it.

Researchers should not record names of any pps: they should use numbers or false names.

Limitations.

1, Sometimes is is possible to work out who pps were on the basis of info provided (e.g. geographical location).

How to deal with it.

Do not observe anyone without their informed consent unless it is in a public place. Pps may be asked to give their retrospective consent or withhold their data.

Limitations.

1, There is no universal agreement about what constitutes a public place from example: lovers on a park bench.

A sample of pps produced by selecting people who are most easily avaliable at the time of the study. (e.g. looking in a coffee shop to see whos there).

+ The easiest method so it takes less time to locate your sample than other methods.

- Inevitably biased because the sample is taken from small part of your target population.

A sample of pps produced by asking for volunteers (usually who respong to advert or poster).

+ Access to a variety of pps which would make sample more representative/less biased.

- Sample is biased because pps are likely to be more highly motivated and / or with extra time on their hands (volunteer bias).

A sample of pps produced by using a random tachnique so that every memeber of teh target population being tested has an equal chance of being selected (so if you were to do a random sample out of a hat each has the same chance of being picked).

+ Unbiased: all members of target population have equal chance of being picked,

- You may end up with a biased sample because the sample is to small i.e more girls than boys.

Demand characteristics: occur when pps guess the purpose of the study and try to act in ways which either help or hinder the research. This is a particualr problem in market research. Pps act nervously or out of character because they are in a research situation or offer answers which they think are socailly desirable.

Investigator effects: include the effect which the investigator has on the behaviour of pps. In a questionnaire / interview study, the ways in which the researcher responds to the pps answers can affect later questions. Other factors such as age, gender etc can also be improtant.

The most frequently occuring score,

Advantage:

• Useful when in data categories.

Disadvantage:

• Not useful when there are several modes,

The middle value of a set of numbers which have been placed in rank order.

Advantage:

• Not affected by extreme test scores.

Disadvantage:

• Not as sensitive as the mean.

The average, calculated by adding all the values together and dividing by the number of scores.

Advantage:

• Makes use of all data.

Disadvantage:

• Can be misrepresentative if there are extreme values.