Research Methods

1. Research Methods Themes of Pychology

2. Research Methods(Table of Contents) • Experimental Method • Variables, operational definitions, etc. (4-13) • Hypotheses (29-32) • Design (34-41) • Sampling (42-53) • Types of Research Methods • Experimental (14-23) • Non-experimental (54-75)

3. Five Research Methods There are five main research methods used in Psychology: 1) Experiment 2) Self-report 3) Correlation 4) Observation 5) Case study We will look at each in turn and discuss the advantages and the disadvantages of each. This knowledge must be remembered and applied when we discuss the 20 core studies in future.

4. Research Methods Experiment (Themes in Psychology)

5. Experimental Method • The main idea behind the experimental method is that of cause and effect. • Cause and effect means that changes in one factor (the independent variable - IV) bring about changes in another (the dependent variable - DV). • To achieve a clear cause and effect relationship, other possible variables should be controlled (CV). • There are three types of experiment; laboratory experiment, field experiment and natural experiment. • All types vary in the amount of control and ecological validity

6. Variables Example • How would you find out if drawing concepts maps was a more effective revision technique than making conventional notes?

7. PPs revise using concept maps Test of learning Score Conditions PPs revise using note-taking Test of learning Score IV DV Variables Example

8. Experiments & Variables • If the DV changes when the IV does, there is assumed to be a causal relationship between them… • …assuming you can rule out other influences on the DV • Important: *correlation doesn’t always mean causation. We can only assume/guess.

9. Experiments & Variables • Extraneous variables: a variable other than the IV that might affect the DV if it is not controlled. • What, besides the revision technique, might affect the DV? • Controls • What could we do to remove extraneous influences on the DV?

10. Experiments & Variables • Confounding Variables - variables that do actually have an effect on the DV. A confounding variable could be an extraneous variable that has not been controlled. 

11. Operational Definitions • Psychologists are generally interested in the human mind. Since we can’t see inside the “mind”, we must measure behavior. • An operational definition is a description of a variable in terms of how it is measured. • a psychological variable is what we cannot see. • an operational definition is what we can see (to allow us to have an idea of what we cannot see)

12. Operational Definition Examples

13. Your Turn

14. Types of Experiments

15. Laboratory Experiment • The research manipulates the IV and controls any variables extraneous (or irrelevant) to the study. • Takes place in a laboratory where conditions are strictly controlled and the IV manipulated and the DV measured • In this way cause and effect can be established. • This is the method most used by psychologists when conducting research

16. Laboratory Experiment Advantages 1. Manipulating one IV and controlling irrelevant variables means that cause and effect can be shown. 2. Many extraneous variables can be controlled (e.g. temperature or noise levels) 3. Replication is possible as standardised procedures are applied. 4. Participants must give some degree of consent, so ethical issues are reduced.

17. Laboratory Experiments Disadvantages 1. Results can be biased by sampling, demand characteristics or experimenter bias. 2. Some regard the process as ‘dehumanising’ (humans like lab rats!) 3. Controlling variables is reductionist as it is unlikely that any behaviour can be truly separated from others

18. Laboratory Experiment Disadvantages 4. Artificial conditions (setting and task) can produce unnatural behaviour. Therefore they lack ecological validity. 5. Participant might be deceived in order to isolate the IV. Maybe other ethical issues. 6. More likely that the data will be snapshot

19. Field Experiments • As in the laboratory experiment the research again manipulates the IV and attempts to control any variables extraneous (or irrelevant) to the study. • Field experiments however take place outside the laboratory in a more natural environment (e.g. classroom or subway)

20. Field Experiments Advantages 1. Greater ecological validity because the surrounding are natural. Can tell us better how people behave in real life. 2. Less likelihood of demand characteristics (wanting to please the experimenter) as people are may be unaware of research taking place 3. Important features of an experiment are maintained (IV, DV and CVs)

21. Field Experiment Disadvantages • 1. Difficulties in controlling the situation and therefore a greater possibility of extraneous variables influencing the result. 2. It might be difficult to replicate effectively. 3. Problems of access to where the experiment is done (e.g. consent from school or company) 4. Ethical problems related to consent, deception, invasion of privacy etc

22. Natural Experiment(Quasi-Experiment) • The conditions of the IV happen by themselves and are not manipulated by the experimenter. • E.g. Whether males or females are more likely to choose science or humanities subjects. • The IV is sex - male or female. This cannot be ‘manipulated’ or controlled- it just happens. • Also referred to as a quasi-experiment.

23. Natural Experiment (Quasi-Experiment) Advantages 1. Greater ecological validity because the surroundings are natural. Behaviour is like real life 2. Less likelihood of demand characteristics as people are unaware of research 3. Features of an experimentare retained (although the IV not actively manipulated).

24. Natural Experiment(Quasi-Experiment) Disadvantages 1. Difficult or impossible to infer cause and effect due to lack of control over extraneous variables and no manipulation of IV. 2. Replication may be difficult or impossible 3. May be subject to bias if the subjects know that they are being observed.

25. Practice • A researcher hypothesizes that blondes really do have more fun. To test this hypothesis, she interviews a natural brunette who has recently become a blonde to determine if there is any change in the amount of fun she has. • Independent variable? • Dependent variable?

26. A developmental psychologist is testing the hypothesis that children in first grade know more words in the English language than children in Kindergarten. To test this, she sits in on two classes (one first grade, the other Kindergarten) and counts the average number of words children in each class speak. She then compares the counts. • Independent variable? • Dependent variable? • Type of study?

27. A clinical psychologist hypothesizes that people who have been diagnosed as having major depression will be more likely to also be diagnosed with an anxiety disorder than will people who have not been diagnosed with major depression. To test this, he gives a survey to 100 people being treated for depression and 100 people with no known mental disorder. The survey asks them to report whether or not they have been diagnosed as having an anxiety disorder. • Independent variable • Dependent variable

28. A pharmacologist is testing whether a new anti-anxiety medication, Moodcor, will cause people to gain weight. To test this, she gives 100 people Moodcor for one month and 100 people a placebo drug. At the end of the month, she monitors any weight gain. • Independent variable? • Dependent variable? • Type of study?

29. A personality psychologist believes that people who are more aggressive are more likely to purchase sports coupes than people who are less aggressive. To test this, he visits local car dealerships and asks car shoppers to complete an aggression survey. Then, he observes what types of cars they purchase (sports coupe, sedan, SUV, or pickup).   • Independent variable • Dependent variable

30. Hypotheses Understanding the Experimental Method

31. Hypothesis • A prediction about the outcome of a piece of research • An experimental hypothesis must predict the effect of the IV on the DV

32. Hypothesis Examples • A researcher dressed in uniform will be obeyed more often than a researcher dressed in civilian clothes. • Words that PPs have processed semantically are more likely to be recognised than words that they have processed structurally.

33. Hypothesis Example • What was the hypothesis for the Bandura and Freud studies?

34. Hypothesis • Directional hypotheses predict the direction in which the results are expected to run • Non-directional hypotheses predict an effect of the IV on the DV, but not a direction

35. Experimental Designs Understanding the Experimental Method

36. Experimental Design • As well as the type of experiment that you conduct, there are a number of ways that experiments can be designed. What we mean by this is the way that the experiment puts people into groups. The three main types: • Independent groups • Repeated measures • Matched participants

37. Compare the results for the two groups Independent groups Recruit a group of participants Divide them into two This group does the experimental task with the IV set for condition 1 This group does the experimental task with the IV set for condition 2 Measure the DV for each group

38. Independent groups • What sorts of problem are likely to arise from using two different groups of people? Problem: The natural variation between the individuals (participant variables) in each group may affect the DV measurements, making it look as if the IV has had an effect when it actually hasn’t Control: After the PPs have been recruited, they should be randomly assigned to their groups. This should ensure the groups are similar, on average.

39. Compare the results for the two conditions Repeated measures Recruit a group of participants Condition 1 Condition 2 The group does the experimental task with the IV set for condition 1 The group repeats the experimental task with the IV set for condition 2

40. Repeated measures • What sorts of problem are likely to arise from using the same group of people twice? Problem: Doing both conditions may (1) give PPs practice on the task; (2) make them bored or tired; (3) allow them to work out the aim of the study, all of which might affect the DV measurement. (4) Reuse of stimuli is not possible. Control: Divide the PPs into two groups. Half does condition A first, then condition B. The rest do condition B then condition A. DV measurements for the conditions A and B are then compared (counterbalancing).

41. Compare the results for the matched pairs Matched participants Recruit a group of participants Find out what sorts of people you have in the group Recruit another group that matches them one for one Treat the experiment as independent measures Condition 1 Condition 2

42. Matched pairs • What sorts of problem are likely to arise from using matched pairs of PPs? Problem: Several problems: (1) time consuming; (2) an exact match is rarely possible; (3) if one PP drops out you lose 2 PPs’ data. Control: Members of each pair should be randomly assigned to conditions. However, this does not solve all these problems.

43. Sampling Understanding the Experimental Method

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45. Sampling • Researchers aim to get a sample that is representative of the target population • Every type of person in the TP should be proportionally represented in the sample • It is not necessary for the sample to be representative of the GP unless the researcher intends to generalise

46. Sampling Methods • Includes: • Opportunity sampling • Random sampling • Stratified sampling • Volunteer sampling

47. Opportunity Sampling Geek! Want to be in my study? Common Room Opportunity sampling is the sampling technique most used by psychology students. It consists of taking the sample from people who are available at the time the study is carried out and fit the criteria you are looking for.

48. Opportunity Sampling Strengths • It tends to be more ethical because the researcher can judge if the participant is likely to be upset by the study or is too busy to take part. • The researcher has more control over who is asked, so finding participants should be quick and efficient and costs less money,  • For example the researcher may use friends, family or colleagues.   Weaknesses • The people who are available at the time may well not be representative of the target population as a whole, so the sample will be biased. • The researcher may have more control over who is chosen and choose certain people, leading to a biased sample.

49. Random Sampling This is a sampling technique which is defined as a sample in which every member of the population has an equal chance of being chosen. This involves identifying everyone in the target population and then selecting the number of participants you need in a way that gives everyone in the population an equal chance of being picked.

50. Random Sampling Strengths • There is no bias in the way that the participants are selected, everyone has an equal chance of being selected. Therefore the sample is likely to be representative of the target population. Weaknesses • Random sampling can be very time consuming and is often impossible to carry out, particularly when you have a large target population, of say all students.  For example if you do not have the names of all the people in your target population you would struggle to conduct a random sample.   • Other issues people may not be available on the day, or they simply do not wish to take part in the study so there could be bias.