Understanding the Scientific Method: Aims, Hypotheses, and Controlling Biases, Slides of Research Methodology

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A03 - How Science Works

Observe human behaviour Develop explanations (theory)/hypotheses Test hypotheses Collect results/data Draw conclusions Analyse data/graphs/inferential statistics

Aims and Hypotheses

• AIM - a general statement of WHY a study is being carried out. E.g To test the Multi Store Model of memory.
• HYPOTHESIS – states precisely WHAT you expect to SHOW or BELIEVE to beTRUE. E.g. It takes longer to read a list of conflicting words than non-conflicting words.
• NULL hypothesis (Ho) – states that the IV has no effect on the DV, e.g. ‘Semantic processing will have no effect on the amount of recall from LTM.’

Aims and Hypotheses

• DIRECTIONAL Hypothesis-
• A specific direction is predicted
• E.g. ‘People who do homework without the TV on will do better than those who do homework with the TV on’
• Choose this type of hypothesis if you have an idea about what might happen, as you have read previous research One tailed – you know which direction the expt will go in

Aims and Hypotheses

• NON-DIRECTIONAL hypothesis – no specific direction is predicted.
• E.g. ‘ There is a difference between work produced in noisy or silent conditions.’
• This doesn’t say what the difference will be
• Choose this type of hypothesis if you are not sure what will happen 2 tailed – the results could go either way!!

Over to you ..

Extension work Read p 73 and 74 of your text book. Answer q 1-3 p73, and ‘Think Creatively’ on p

• Try the worksheet

‘Directional or Non-

directional?’

• Now try ‘Writing

hypotheses’

• Have a break

9

Controlling Research Bias

• Teach each other about the type of Bias you have researched - fill in the summary sheet
• Add in how each type is controlled 11

Research Biases

1.Placebo effect – involves the influencing of performance due to the subject’s belief about the results., e.g

• if I believe the new medication will help me feel better, I may feel better even if the new medication is only a sugar pill. This demonstrates the power of the mind to change a person’s perceptions of reality.

Controlling Bias

• Random Assignment - assigning the subjects to each group based on chance rather than human decision.
• To control for the placebo effect, subjects are often not informed of the purpose of the experiment.

Controlling Bias

• (^) This is called a Blind study, because the subjects are blind to the expected results.
• To control for experimenter biases ,

we can utilize a Double-blind study,

which means that both the experimenter and the subjects are blind to the purpose and anticipated results of the study.

Plenary

• Try the worksheet ‘ Sort it out’ 17

Reliability and Validity

• (^) Reliability of results is very important. Can we trust the results?
• If a study is replicated the findings should be similar.
• Validity, does a test measure what it was designed to measure. For example, do IQ tests really measure ‘intelligence’?

Pilot Studies

• A small scale trial run before doing the real thing. Make adjustments to design, helps save money.
• How will this improve ..
• Validity?
• Make sure you are testing the right thing, people may not understand questions or misunderstand instructions, may get bored too many questions
• Reliability?
• Ensure it is replicable

Research Methods in Practice - 1

We are going to take part in a simple experiment After it you will be asked some questions about the experiment. You will each be given a number – 1 or 2 Group 1 and 2 will do a slightly different thing.