Extension: How could psychologists go about carrying out research? Discuss with someone else why you think psychologists carry out research.

By the end of this lesson you will be able: * To describe what is meant by the following: Independent variable (IV), dependent variable (DV), operationalisation. * To apply those terms to research examples.

Theory A theory is a point of view or an idea that a psychologist proposes. Discuss: If a psychologist comes up with a theory – does that mean it is correct? Imagine you wanted to test a theory on helping behaviour and whether people are likely to help strangers. How could you do this?

Study A study is a specific investigation into an area. Studies can be conducted by one or more psychologists. When you describe a study it is common practice to refer to the aim, method, result and conclusion. Psychologists often carry out studies to test whether their theories are accurate.

Method This refers to the way in which a study was carried out. There are many different methods that psychologists use to collect data, depending on what they want to investigate. Experiments Laboratory Natural Field Quasi

In an experiment, the researcher will always have something in mind that they want to investigate in relation to what, if any, effect it has on an aspect of behaviour. * The Independent Variable is the variable which the experimenter manipulates (IV). * The Dependent Variable is the variable that the experimenter measures. (DV). * The dependent variable depends on the independent variable. * Think of it like this….. “If I do so and so (IV)….then such and such will happen (DV)”.

* Example 1 * Imagine a researcher wanted to find out who drives faster, men or women. They would need to gather a number of men and women and record each of their speeds over a stretch of road. * The Independent Variable would be whether the participant was a man or a woman (This is what they are comparing / manipulating). * The Dependent Variable would be the measure of speed.

* What if you were interested in seeing whether your memory for words was better if the words were organised (put into categories e.g. fruit, animal etc) when learnt, rather than if they were random. * The Independent Variable would be whether the words were organised or random when learnt. * The Dependent Variable would be the number of words recalled (this is what you would measure).

* 1) An experimenter believed that Horlicks helps people to sleep and decided to put this to the test. 30 volunteers took part in the study. 15 of the participants drank Horlicks before going to bed whilst the other 15 drank an equal quantity of water. The number of minutes that participants took to fall asleep was recorded. * IV = * DV =

*2*2 ) A researcher wanted to see whether there was a difference in reaction time between seeing (visual) information and hearing (auditory) information. *I*I V = *D*D V =

* 3) An experimenter wished to find out whether pleasant music would increase a person's liking of a stranger. Participants were introduced to an unfamiliar person and spent half an hour chatting to them. Half of the participants had pleasant music in the background, whilst the other half did not. They had to rate how much they liked the other person on a scale of 1-5. * IV = * DV =

* Remember to think of the IV as an ‘OR’ situation. Ask yourself…”What different situations does the researcher use? This…. OR…. This?” * Remember the DV as MEASUREMENT. This could be time, size, temperature, movement, volume etc. Ask yourself “What is the researcher going to make a note of?” Read through the description of variables in your RM booklet and complete the corresponding activity

* When you are writing the IV and DV in a study, they have to be written specifically. * You cannot use a term that is too vague, as if you do, then it makes it difficult for someone else to replicate the experiment (more on this later!).

* Consider the following experiment: * A researcher investigates the influence of alcohol on memory. * What are the IV and DV in this experiment? What difficulties would you have trying to replicate this experiment? Why? Extension: How could you make the IV and DV clearer and more specific?

* A researcher investigates the influence of alcohol on memory. * How can the experimenter operationalise the IV and DV? IV – alcohol or no alcohol. DV - memory IV – whether participants receive no alcohol or 50ml of vodka DV – The amount of words recalled from a list of 20 Operationalised

* A researcher investigates the effect of height on helpfulness. * How could you operationalise the IV and DV in this experiment? IV – height DV - helpfulness Operationalised IV –5ft 10 and over or under 5ft 10 DV – How many people stop to help somebody in the street who has dropped their bag.

* IV – Gender * DV – Obedience IV – Word order DV – Memory IV – Stress DV - Happiness Extension: Make up examples of your own.

Are you now able to do the following: * Describe what is meant by the following: Independent variable (IV), dependent variable (DV), operationalisation? * Apply those terms to research examples?

Due next lesson: 1) Complete the IV and DV activities in your activity booklet (if you haven’t already) 2) Find a study in an AS textbook and identify the operationalised IV and DV. Preparation for next lesson: Think about what other factors may influence our results other than the IV.