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Research Methods Themes of Pychology. Research Methods (Table of Contents) Experimental Method – Variables, operational definitions, etc. (4-13) Variables,

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Presentation on theme: "Research Methods Themes of Pychology. Research Methods (Table of Contents) Experimental Method – Variables, operational definitions, etc. (4-13) Variables,"— Presentation transcript:

1 Research Methods Themes of Pychology

2 Research Methods (Table of Contents) Experimental Method – Variables, operational definitions, etc. (4-13) Variables, operational definitions, etc. (4-13) – Hypotheses (29-32) Hypotheses (29-32) – Design (34-41) Design (34-41) – Sampling (42-53) Sampling (42-53) Types of Research Methods – Experimental (14-23) Experimental (14-23) – Non-experimental (54-75) 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 Variables Example PPs revise using concept maps Test of learning Score PPs revise using note-taking Test of learning Score IVDV Conditions

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 Psychological VariableOperational Definition MemoryNumber of words recalled on a list IntelligenceThe number of various types of problems answered in a limited amount of time (IQ test) HappinessThe number of times someone smiles or laughs during an activity.

13 Your Turn Psychological VariableOperational Definition Agression Stress Reading Ability Depression

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 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 Compare the results for the two groups Independent groups

38 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 Repeated measures Recruit a group of participants Condition 1Condition 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 Compare the results for the two conditions

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 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 Condition 1Condition 2 Compare the results for the matched pairs Treat the experiment as independent measures

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

44 Sampling                               General population Target population Sample General population Target population Sample

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 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. Want to be in my study? Geek!

48 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 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 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.

51 Stratified sampling involves classifying the population into categories and then choosing a sample which consists of participants from each category in the same proportions as they are in the population. = 60% female 40% male = 60% female 40% male

52 Strengths Stratified sampling is an efficient way of ensuring that there is representation from each group. Random sampling would probably still provide some participants from each group, but the researcher cannot be sure of this and may therefore need a larger sample. Stratified sampling limits the numbers needed to obtain representation from each group. Weaknesses However, stratified sampling can be very time consuming as the categories have to be identified and calculated. As with random sampling, if you do not have details of all the people in your target population you would struggle to conduct a stratified sample.

53 Self selected sampling (or volunteer sampling) consists of participants becoming part of a study because they volunteer when asked or in response to an advert. Volunteers needed for psychological study on learning Sounds rubbish… Gotta do my hair.. I just love to be helpful…. I’ve always wanted to be in a study….

54 Strengths The main advantage of a volunteer sample is that participants will all be happy and willing to participate, and they will not feel coerced in any way. Weaknesses The main disadvantage of an opportunity sample is that it will be biased towards a certain type of person as only people with a personal interest in the research topic will volunteer. The sample will not therefore be truly representative of the target population.

55 Research Methods Non-experimental Methods

56 Non-Experimental Methods Psychologists do not have to use experimental methods to investigate behavior. Other methods inlcude: – Observational studies Naturalistic, controlled, participant – Self Reports Questionnaires and interviews – Case Studies

57 Research Methods Self-Report (Themes in Psychology)

58 Self-Reports Self-report: providing the opportunity for participants to report on their own behaviour or experiences. This may include questionnaires, interviews, thinking aloud or diaries. When deciding on a method for self reporting, there are three things to take into account; 1. The Method. In the AS, this is basically a choice between a questionnaire or interview. 2. The format and structure of the questions 3. The way in which the participants will provide answers.

59 Self –Report (questionnaires) Questionnaire: Where participants read the questions for themselves and then fill in the answers for themselves. Data can be quantitative (numbers) or qualitative (words). Remember the advantages and disadvantages of these to help with your evaluation. Questions can be open-ended: free response with no predetermined way to answer) They can be sent by post or filled in online, allowing anonymity. Advantages/disadvantages of post or online?

60 Self-Report (Questionnaire) Questions can be closed-question (choosing from a range of pre- determined answers). a simple yes/no A choice from categories (0-6, 7- 12 etc) A choice from a number scale or Likert scale (strongly agree 1 2 3 4 5 strongly/disagree) Is there a difference between a 4 point and a 5 point scale? (advantages or disadvantages?)

61 Self-Report (Interviews) Interview: where questions are asked of aparticipant and the interviewer notes theresponses. Interviews can be; 1. Structured: the questions are preprepared and every participant receives the same questions in the same order without variation. 2. Unstructured: there is no pre-preparation of questions and questions are asked depending on the direction that the discussion goes, or the questions are open- ended. 3. Semi-structured: Some structured questions and some unstructured/open ended questions. Face to face or by telephone. Anonymity?

62 Self-Report (Interviews) Closed questions resulting in quantitative data may provide percentages, but not the important ‘Why?’. Adding an open-ended question such as ‘please give a reason for your answer’ can solve this. Are there advantages and disadvantages to answering face to face compared with telephone interviews? Face to face interviews can lead to answers which are ‘socially desirable’

63 Self-Report Advantages 1. Participants can express a range of feelings and explain their behaviour. 2. Data may be rich and detailed (open ended q’s) 3. Both qualitative and quantitative data is possible. 4. Closed questions are easier to analyse (score). 5. Large numbers of participants can be dealt with quickly and potentially cheaply (greater generalisability). 5. Questionnaires are easy to replicate

64 Self-Report Disadvantages 1. Closed questions can be restrictive and dont supply the ‘why’. 2. Participants might be more likely to give socially desirable answers. 3. Closed questions might force participants to give a answer which is not truly reflective. 4. Researchers need to be careful of ‘leading questions’ during unstructured interviews, affecting validity. 5. Open-ended questions can be time consuming to analyse. 6. May be some confusion during telephone interview

65 Research Methods Observations (Themes in Psychology)

66 Observation Observation: data is collected through observing or watching participants with the aim of recording the behaviour that is witnessed. Three are three types of observation; 1. Controlled observation 2. Natural observation 3. Participant observation

67 Controlled Observation Controlled Observation: takes place in a controlled environment such as an laboratory. The participant is given a particular task and the observer may record data either from inside the same room or through a one way mirror (or by video camera). Bandura’s Bobo doll experiment is a good example

68 Natural Observation Natural Observation: takes place in a natural environment. The location and task is natural for the behaviour the researcher is interested in. The recording of behaviour using this method can be much more problematic because the aim is for the participants to be unaware that they are being observed (natural behaviour). Piliavin’s subway study is a good example of this

69 Participant Observation Participant Observation: the observer or researcher becomes a member of the community they are observing. This can be ‘overt’ observation where the community knows that they are being observed. It may also be ‘covert’ where the observation is done in secret

70 Recording Observational Data There are two types of observation; structured and unstructured. Unstructured Observation: is where the observer records all of the behaviours, with no predetermined ideas or categories

71 Recording Observational Data Structured Observation: the researcher has a predetermined schedule, coding scheme, tally chart or set of categories (response categories). These can simply be ticked when a behaviour is observed. Structured observation can use: Event sampling: looking for, and recording specific behaviours Time sampling: records certain behaviours at certain time

72 Observation Advatages 1. The observed behaviour is natural, so high in ecological validity. 2. Data is often quantitative so it is objective and statistics can be applied. 3. Data can be extremely rich if unstructured or participant observation is used. 4. If the participants are unaware of the observation, they are unaffected by demand characteristics.

73 Observation Disadvatages 1. Participants cannot explain ‘why’ the behaviour has occurred. 2. Observations may not be reliable, e.g. obstructed view. 3. Natural observation lacks control (cause and effect) 4. Unstructured observation can lead to observer bias; seeing things they want to see. 5. Mis-recording of information (observer mistakes) 6. Might be very difficult to replicate natural observations as every natural situation is unique. 7. Unethical as people are being observed without their consent, and maybe with deception.

74 Research Methods Case Studies (Themes in Psychology)

75 Case Study Case Study: a detailed piece of research involving a single participant, group under treatment or ‘unit’. It gives rich and detailed information information about a ‘unique’ behaviour. (e.g. Clive Wearing) Some argue that this is a fascinating part of Psychology. Others would say that it is not scientific at all. No generalisability. Little Hans is a good example. Freud actually admitted that Little Hans was not a normal child, and that his case study had no scientific value

76 Case Study Advantages 1. In some cases it is impossible to have a large number of participants. Rare or unique behaviours can be studied. 2. Participants can be studied over a period of time, so developmental changes can be recorded. 3. Sample may be self selecting, not chosen by researchers. 4. Ecological validity is very high, participant is studied as part of everyday life. 5. Data can be rich and detailed.

77 Case Studies Disadvantages 1. Rarely produce enough quantitative data for statistical analysis. 2. Researcher may lack objectivity due to a close relationship with the participant. 3. Conclusions cannot be generalised because only one, or a few participants are involved. 4. Participants might be totally unique, or ‘not normal’ leading to false conclusions being drawn.

78 Case Study example: Phineas Gage an American railroad construction foreman remembered for his survival of an accident in which a large iron rod was driven completely through his head, destroying much of his brain's left frontal lobe. Effected his personality and behviour for the rest of his life. His friends no longer saw him as Gage


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