Edexcel Psychology for A Level Yr 1 / AS Revision Guide

Experiments 123 Check it 1. Compare the use of field and laboratory experiments in cognitive psychology. [4) 2. Ravy is conducting a field experiment on facial recognition. Explain how she might go about this, with reference to the independent and dependent variables and any controlled variables. [5) Spec spotlight 2.2.1 Designing and conducting experiments, including field and laboratory experiments. 2.2.2 Independent and dependent variables. Strengths and weaknesses of the two types of experiment are on page 126. Check it 1. Martha’s teacher claims that mind maps help with remembering facts more than creating linear notes. (a) Write an experimental and null hypothesis that Martha could use to test this claim. [2) (b) Write a null hypothesis for Martha’s teacher’s study. (2) Spec spotlight 2.2.3 Experimental and null hypotheses. 2.2.4 Directional (one-tailed) and non-directional (two-tailed) tests and hypotheses. 2.2.6 Operationalisation of variables. A hypothesis is not a question.This is a research question: Do people who sleep more do better at school? A hypothesis is not an aim.This is a research aim:To investigate whether sleeping more means that your memory is better. A hypothesis is a statement of what is believed to be ‘true’, stated in present tense. It is a statement about the whole population rather than just the sample and therefore it is about people not participants. Experimental hypothesis Abbreviated as H 1 A statement about the effect of the IV on the DV. A hypothesis should include both levels of the IV. A hypothesis should be precise and testable (i.e. operationalised). Direction of hypothesis Directional ( one-tailed ) hypothesis states direction of the hypothesis (e.g. one condition is more than another). • e.g. People who sleep for eight hours do better than those who sleep for five hours. Non-directional ( two-tailed ) hypothesis just states there is a difference. • e.g. People who sleep for eight hours perform differently on a memory test from those who sleep for five hours. Null hypothesis Abbreviated as H 0 This is a statement of no difference (NOTE: do not use the term ‘relationship’). • e.g. There is no difference between the memory test scores of people who sleep for eight hours and those who sleep for five hours. A research method which demonstrates causal relationships. All experiments have an IV and a DV. Variables IV and DV. Independent variable (IV) – directly manipulated by the experimenter. Dependent variable (DV) – measured by experimenter to assess effects of IV. At least two levels of the IV in an experiment. Operationalisation Variables must be defined in a way that they can easily be tested. Types of experiment Laboratory experiment Experiment conducted in a very controlled environment (participants go to the experimenter). IV manipulated by experimenter. Field experiment Experiment conducted in more everyday surroundings than a laboratory (experimenter goes to participants). IV manipulated by experimenter, DV may be measured in a laboratory or in the ‘field’. Hypotheses