Section AExperiments

Example Section A

1.State the null hypothesis for your practical project. (4)

2.Describe a method you would use to conduct your practical project. (19)

3.Give an advantage of using an alternative experimental design in this practical project. (3)

4.Assess the validity of your investigation in measuring the dependent variable. (6)

5.Outline how you could select a sample which would be representative. (3)

6.What ethical issues would you consider in designing your practical project? (3)

7.Suggest one idea for possible future research related to your practical project. (3)

ExperimentsLOs: To recap key information about experimentsTo evaluate the strengths and weaknesses of the experimental methodTo apply this knowledge to the exam

What can you remember about:

• The key features of the experimental method

• How you control variables• What the strengths and weaknesses of experiments

are• What are the different types

of experimental design?

Ext: strengths and weaknesses of types of experimental

design

Types of experiment

Lab

Field

Quasi

Remind me what these are???

Types of design Independent measures

Repeated measures

Matched pairs

Complete the description and evaluation worksheets. This is revision so should not take you more than 15 minutes.

Key definitions

Independent variable:

Dependent variable:

E.g. red blood cell count

Key definitions

Alternate/Experimental Hypothesis H1A hypothesis is a testable, predictive statement. The hypothesis will state what the researcher expects to find out. When a hypothesis predicts the expected direction of the results it is referred to as a one-tailed hypothesis.

When a hypothesis does not predict the expected direction of the results it is referred to as a two-tailed hypothesis.

How you should formulate your alternate or experimental hypothesis:

There will be a significant difference between IV (operationalised) and DV (operationalised)

There will be a significant difference between gender (male and female) and IQ (measured by their score on a 100 pt IQ test).

Females will have a significantly higher IQ (measured by their score on a 100 pt IQ test) than males.

Key definitions

Null Hypothesis H0

The null hypothesis is not the opposite of the alternate hypothesis it is a statement of no effect.

The null states that there will be no difference as a result of the IV.

There will be no difference between gender (male and female) and IQ (measured by their score on a 100 pt IQ test).

IV/DV WorksheetNull and Experimental Hypothesis

In pairs identify the IV and DV and then the Experimental/Alternate Hypothesis and the Null Hypothesis

In groups outline your experiment

What is your research question?

Aims

Design and why it is good

Target population and expected sample

Sampling technique

IV and DV

Groups and allocation to them

Materials used

Procedure

What extraneous variables there might be

How you will control extraneous variables

Ethical issues to be considered

What form your data will take – how will you collect it and how will you analyse it?

Will you have a control group?

Inferential Statistics (we will cover this separately later)

Design TaskIdeas????

You have this info on your sheet.

Always link your decisions to reliability and validity.

Plenary

Explain your research idea to the rest of the class.