# Laura Priestley

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## Aims and Hypotheses

Alternate Hypothesis (Experimental Hypothesis): A specific testable statement that predicts the expected outcome of a study. An alternate hypothesis states that there will be a difference/relationship between the variables being investigated.

Null Hypothesis: States there will be 'no specific difference' or 'no significant relationship' between variables under investigation.

One-tailed hypothesis: Predicts the direction that the difference will take. It is directional. E.g. particpants under the age of 30 year will recall significantly more items than particpants aged 60 or above.

Two-tailed hypothesis: Non-directional. Merely states that there will be a signifcant difference between those particpants given a categorised list compared to those given a randomised list. E.g. There will be a significant difference between those participants given a categorised list compared to those given a randomised list.

Correlational hypotheses: Predict significant patterns of relationship between two or more variables. Involves co-variables not independent and dependent variables.

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## Operationalising Variables

Operationalising means making something clear or unambiguous. The process of devising a clear way of measuring something so that another person knows exactly what you have done.

Operationalising the IV: How is the IV organised?

Operationalising the DV: How is the DV measured?

Example: 'Girls do better at school than boys'

IV: Gender... gils/boys

DV: The difference in exam results in boys and girls

Normal hypotheses: Students learn better earlier in the day

Operationalised hypotheses: Students will recall significantly more words out of a possible 20 when they re tested at 9:00am than when they are given the same test at 2:00pm.

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## Population and Sampling

Opportunity Sampling

•  Quick and convinent
• Although, bias and unrepresntative

Self-selected sampling

• Ethical and informed consent
• Although, bias and unrepresentative

Random Sampling

• Equal chance of being selected and creates an unbiases sample
• Although, true random sampling is rare

Snowball Sampling

• Allows you to get specialist sample
• Although, it is time consuming
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## Rating Scales

Likert Scales

Particpants have to indicate how much they agree or disagree with a given statement.

E.g. Strongly agree, agree, neither agree or disagree, disagree or strongly disagree.

Semantic Differantial

Clean : : : : : : : : : : : :: : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : Dirty

E.g. you circle which one is closer to the side you agree with

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## Questionnaires and Interviews

Questionnaires

• Can be easily repeated so that data can be collected from a large number of people relatively cheaply and quickly
• May be wiling to reveal personal/confidental information than in an interview
• - Answers may not be truthful, e.g. because of leading questions and social desirability bias
• The sample may be biased because only certain kinds of people fill in questionnaires

Structured Interview

• Can be easily repeated and requires less skill than unstructured interviews
• Interviewers expectations may influence the answers the interviewee gives, called interview bias.
• Want to present themselves in a good light and thereofre give socially desirable answers which is called social desirabilty bias
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