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Methodology A

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					     LEVEL TWO

RESEARCH METHODS IN
    PSYCHOLOGY



                      1
            Your course lecturer

•   Colin Gray
•   Room S16 William Guild Building
•   E-mail address: c.gray@abdn.ac.uk
•   Telephone: (27) 2233
•   Don’t hesitate to get in touch with me if
    you have any queries or encounter any
    difficulties.
                                                2
             About the course
• Twelve lectures.
• I give my lectures during the first half-session,
  but some topics will be useful for the work you
  will be doing after Christmas as well.
• The lectures are integrated with other courses
   – the practicals
   – the workshops on using the computer to analyse data
• A multiple-choice examination.


                                                       3
            To help you …
• I shall try to arrange that the overheads for
  each lecture are on the Web before the
  lecture is given.
• I shall give you plenty of examples of
  multiple-choice questions for practice.
• There’s no need for anyone to fail this
  course, but I recommend that you
  PRACTISE AS YOU GO ALONG.
                                              4
       Purpose of the course
• Psychology is a very wide field of enquiry.
• Different research questions can require
  quite different methods.
• General principles of good research
• Psychological research produces
  numerical data.
• How to make sense of psychological data

                                                5
              To statisticians
• In these lectures, I shall discuss only the most
  elementary statistical methods.
• If you have already taken a statistics course, you
  may find some of my later lectures too easy.
• Attendance is not obligatory. Check out each
  lecture on the Web first.
• Inspect the exam papers in the library to make
  sure that you are adequately prepared.


                                                   6
          Course textbook
Kinnear, P. R., & Gray, C. D. (2006).
SPSS 14 made simple. Hove & New
York: Psychology Press.

This book covers most of the topics in this
course of lectures.

It will be useful to you next year if you
continue with psychology.
                                              7
For a broader view of strategies in
      psychological research




                                      8
         Lecture 1

STRATEGY IN PSYCHOLOGICAL
       RESEARCH



                        9
Psychological research is different
from research in a natural science,
   such as physics or chemistry




                                  10
                 Physics
• ‘If you’ve seen one alpha particle, you’ve
  seen them all’ (Moore, 1985; p75).
• In physical sciences, the units of study are
  usually identical.
• So what is true of ONE alpha particle is
  true of ALL alpha particles.



                                             11
                 Chemistry
• In chemistry, there are books giving the values
  of ‘Physical Constants’.
• In pure form and under specified conditions,
  each substance has fixed properties such as a
  melting point and a boiling point.
• What’s true of YOUR potassium permanganate
  is true of ALL potassium permanganate.
• To discover the properties of your potassium
  permanganate (or anyone else’s), just look up
  the book.

                                                    12
There are no constants in
       psychology




                            13
          Human variability

• Look at the people entering a lecture
  theatre.
• They vary in their appearance, their size
  and their physical proportions.
• They vary in their behaviour.



                                              14
           Human variability…
• Their psychological characteristics also vary.
• So do their attitudes and political affiliations.
• Their capabilities also vary.
   – How quickly could you slam on the brakes in an
     emergency?
   – How well can you catch and throw a ball?
   – How quickly and accurately could you identify a guilty
     person in a line-up?



                                                          15
                Variable
• The psychologist must deal with
  VARIABLES.
• A VARIABLE is any characteristic or
  property with respect to which objects,
  people or situations can differ.
• Gender is a variable. Height is a variable.
  The speed with which you can slam on
  your breaks in an emergency is a variable.
                                            16
A key term




             17
      Quantitative and qualitative
               variables
• Variables such as height, weight and ability level
  are characteristics that are possessed IN
  DEGREE. They are QUANTITATIVE variables.
• Characteristics such as gender, nationality and
  blood group are possessed only IN KIND. They
  are QUALITATIVE variables.
• Qualitative variables consist of sets of categories
  and are also known as CATEGORICAL
  variables.

                                                   18
     Continuous versus discrete
             variables
• Quantitative variables can, in turn, be divided
  into those whose values vary CONTINUOUSLY
  (height, weight) and those whose values vary in
  steps, that is, DISCRETELY.
• The number of visits to a website, for example,
  is a discrete quantitative variable.
• So also is the number of heads obtained on ten
  tosses of a coin.


                                                    19
 Continuous versus discrete …
• A discrete variable can take only a finite
  number of values between any two points
  on the scale.
• A continuous variable can take an infinite
  number of values between any two points
  on the scale.



                                               20
              Measurement
• A MEASUREMENT or DATUM is a numerical
  record of a value (or category) of some variable
  you are studying.
• A quantitative variable can be measured on an
  independent scale with units, such as a ruler, a
  weighing machine or a psychological test. This is
  ‘measurement’ in the everyday sense of the
  word.
• I am going to use the word ‘measurement’ in a
  more general way to include both quantitative
  and qualitative variables.
                                                 21
            Measurement…
• Qualitative variables can be recorded by using
  arbitrary code numbers, such as 1 for females
  and 2 for males. These are also
  ‘measurements’, in the sense that they are
  numerical records of observations.
• Here, however, the numbers are merely acting
  as CATEGORY LABELS. The numbers 9 and 99
  (for females and males, respectively) would
  serve just as well.

                                              22
                   Data
• Measurements are also known as DATA.
• DATA (Latin) is the plural form of DATUM.
• Please write, ‘The data ARE interesting’ or
  ‘These ARE interesting data’, rather than
  ‘The data IS interesting’ or ‘This IS
  interesting data’.



                                            23
       Establishing causality
• We don’t gather data just for the sake of it.
• In psychological research, the researcher
  is often trying to show that some variables
  have CAUSAL EFFECTS upon others.
• Does the watching of violent films make
  people more violent?
• Do certain drugs improve memory?
• Alzheimer’s disease. Violent pornography
  on the internet.
                                              24
                   Hypotheses
• Research is motivated by a desire to confirm (or refute)
  a supposition, or HYPOTHESIS, about nature.
• Often, a hypothesis is a statement to the effect that one
  variable affects, or causes, another.
• It might be hypothesised, for example, that learning
  speed initially increases with food deprivation but
  declines after an optimal level of deprivation has been
  reached.
• It might be hypothesised that the more violent
  programmes that children watch on TV or cinema the
  more violent the children actually become.


                                                              25
        Three strategies in
       psychological research

1. Experimental
2. Correlational
3. Observational




                                26
      Which method is best?
•  There is no ‘best’ method. The choice
   depends upon
1. The research question
2. The state of knowledge in the area
3. The circumstances – access to
   participants, etc.
• Ethical considerations may also
   constrain the researcher’s choice of
   strategy.
                                           27
               Causality

• Of the three research strategies,
  experimentation can yield the strongest
  evidence for causality.
• It is much more difficult to establish
  causality with the other approaches.



                                            28
     1. Experimental research
• In experimental research, the
  experimenter MANIPULATES one variable
  to demonstrate that it has a CAUSAL
  EFFECT upon another, which is
  MEASURED or recorded during the
  course of the experiment.
• Such manipulation is the hallmark of a true
  experiment.

                                            29
        The independent and
        dependent variables
• The manipulated variable is known as the
  INDEPENDENT VARIABLE (IV).
• The measured variable is known as the
  DEPENDENT VARIABLE (DV).
• The experimental results should show
  whether the IV has a causal effect upon
  the DV.
                                             30
             An experiment
• Does food deprivation affect speed of
  learning?
• Participants are tested on learning speed
  after different periods of food deprivation.
• Here, the IV (independent variable) is
  amount of deprivation and the DV
  (dependent variable) is learning speed.


                                                 31
A summary of the results




                           32
The true relationship?




                         33
     The independent variable

• Note that deprivation (the IV) is NOT a
  property of the participants in the study – it
  is a variable MANIPULATED by the
  experimenter.
• Learning speed (the DV), however, IS a
  property of the participants and is
  measured during the course of the
  experiment.
                                               34
         Direction of causality
• The concept of ‘cause’ raises many problems.
  Whole books have been written about it.
• But from the results of this experiment, it is
  difficult to escape the conclusion that amount of
  deprivation has a lawful effect upon learning
  speed.
• Initially, the effect of a little deprivation is to
  increase speed; but eventually, with increasing
  levels of deprivation, speed is impaired.
• The research hypothesis is supported by these
  data.

                                                        35
    2. Correlational research

• In CORRELATIONAL RESEARCH, all
  variables are measured as they occur in
  the participants.
• There is NO MANIPULATED VARIABLE.
• All variables are properties or
  characteristics of the people we are
  studying.
                                            36
     Screen violence and actual
              violence
• Does watching violent material promote
  actual violence in real life?
• Ethical and practical considerations make
  it difficult to manipulate the amount of
  violent material that children watch.
• It is easier to measure children on the
  amount of screen violence to which they
  are exposed (or choose to view) and upon
  their actual violence.
                                          37
        A study of violence
• We devise a scale measuring actual
  violence.
• We devise another scale measuring
  amount of exposure to violent
  programmes.
• We measure some children on both
  Exposure to screen violence and Actual
  violence.
                                           38
            A scatterplot
                     • Here is a picture of the
                       results of our study.
Richard              • In this SCATTERPLOT,
                       each point represents
                       one of the children.
                     • Richard got a score of 2
              John     on Exposure and 4 on
                       Actual.
                     • John got 9 on Exposure
      Jim              and 8 on Actual.
                     • Jim got scores of 5 on
                       both Exposure and
                       Actual.

                                                  39
                Correlation
• A statistical ASSOCIATION or CORRELATION
  is a tendency for events or values to occur
  together.
• If exposure to screen violence promotes actual
  violence, we should expect those who watch
  more violence to be more violent and those who
  watch less to be less violent. We can expect an
  ASSOCIATION or CORRELATION between
  Exposure and Actual violence.

                                                40
A strong correlation

          • A correlation is evident
            from the scatterplot.
          • When the shape of a
            scatterplot is a narrow
            ellipse like this, a strong
            correlation is indicated.
          • This correlation is about
            .85.



                                          41
Scatterplot indicating no
      association
             • When the cloud of
               points is circular,
               there is NO
               ASSOCIATION
               between the
               variables.
             • We can expect the
               correlation to be
               about ZERO.

                                     42
Have we really gathered evidence
      for the hypothesis?




                               43
A famous dictum


CORRELATION
  does not imply
 CAUSATION



                   44
            A causal model




• The hypothesis implies this CAUSAL MODEL.
• The results are CONSISTENT with the
  hypothesis.
• The correlation may indeed arise because
  exposure to violence causes actual violence.
                                                 45
        Another causal model




• The child’s violent tendencies towards and
  appetite for violence lead to his watching violent
  programmes as often as possible.
• This model is also consistent with the data.

                                                   46
      Yet another causal model




• NEITHER variable causes the other.
• Both are determined by the behaviour of the
  child’s parents.
                                                47
         Direction of causality
• Returning to the deprivation experiment, it would
  be ridiculous to suggest that learning speed
  determines deprivation.
• In the violence study, however, which was of
  CORRELATIONAL, rather than
  EXPERIMENTAL design, the direction of
  causation is uncertain.
• Indeed, at least three possible MODELS OF
  CAUSATION are consistent with the results.

                                                  48
Characteristics of an experiment
•    The deprivation experiment embodies two essential
     features of a true experiment.
1.   COMPARISON.
2.   CONTROL.
•    To show that one variable influences another, we must
     have a point of reference. Here we can compare
     ‘baseline’ performance with performance under varying
     degrees of deprivation.
•    We must also be able to ‘control’ the experimental
     conditions effectively. In this case, the volunteers were
     prepared to have their food intake controlled by others
     over the period of the experiment.

                                                            49
Stroop interference
          • You are asked not to
            READ the words, but to
            NAME the COLOUR of
            the print each time.
          • It’s difficult to do, because
            the natural tendency is to
            read the word.
          • The more words there
            are, the more difficult it
            gets.


                                       50
         Demonstration versus
           experimentation
• The Stroop task is obviously difficult.
• But you have not participated in a true
  experiment.
• There is no element of comparison here: there
  was only one condition.
• We need to compare the task you have just
  attempted with the task of naming the same
  colours in an array similar to that used for the
  words.
• We need a comparison or CONTROL condition.

                                                 51
        The rule of one variable in
          experimental design
• In a true experiment, there must be at least two
  conditions.
• If there are just two conditions, one of them is usually a
  comparison or CONTROL condition.
• The comparison or CONTROL condition must differ from
  the active or EXPERIMENTAL condition only in the
  absence of the active agent. In all other respects, the
  two conditions must be identical.
• In the Stroop experiment, participants must also be
  asked to name the colours of non-word patterns.


                                                           52
A control (comparison) condition
                • In fact, it is much
                  more difficult to name
                  colours than to read
                  words.
                • Even so, Stroop
                  (1935) showed that it
                  takes much longer to
                  name the print colour
                  of the conflicting
                  colour words.
                                       53
     Extraneous or confounding
             variables
• It is often very difficult to devise an
  appropriate control condition in
  accordance with the rule of one variable.
• If the control condition differs from the
  experimental condition in more than one
  way, this characteristic may be entangled
  or CONFOUNDED with the independent
  variable.

                                              54
    3. Observational research
• In the third kind of research, the
  researcher neither manipulates variables
  nor measures them as they occur in
  participants.
• In OBSERVATIONAL RESEARCH, the
  researcher simply records what the
  participant says and does.


                                             55
            Natural history
• As examples, we have the classic
  observational studies of animal behaviour.
• In his book King Solomon’s Ring, the
  naturalist Konrad Lorenz describes his
  highly influential observations on such
  behaviour as imprinting in ducklings.
• The French entomologist Jean-Henri
  Fabre observed and described the
  behaviour of the hunting wasp.
                                           56
             Case histories
• In psychology or psychiatry, the
  counterpart of the natural history study is
  the CASE HISTORY, the reports of
  Sigmund Freud and Kraftt-Ebbing being
  classic examples.




                                                57
       The participant observer
• What causes football violence?
• Researchers have infiltrated football gangs and
  attempted to discover the social dynamics of violence.
• Big business makes extensive use of techniques of
  persuasion, and not just in advertising. The Tupperware
  organisation trained a large staff to organise parties at
  which those present were persuaded to host their own
  parties later. Specially trained Tupperware personnel
  would bring great pressure to bear upon guests to make
  a commitment to host their own parties at some specified
  future date.
• The Tupperware training methods have been described
  by Taylor (1975), who arranged for members of his
  research team to infiltrate a Tupperware group and
  observe their methods.
                                                         58
Phenomenology: Enquire within
• PHENOMENOLOGY (Brentano) is a
  philosophical doctrine which held that
  psychology should be based upon
  IMMEDIATE EXPERIENCE.
• There have always been psychologists
  who argue that psychology should be less
  about numerical data and more about
  people’s descriptions of how things seem
  to them personally.

                                         59
                Introspection
• The principal research tool of the
  phenomenologist is INTROSPECTION, which is
  description of one’s own thoughts and
  experiences.
• This method is still used in modern psychology,
  as when chess players and other problem-
  solvers are asked to ‘think out loud’ as they play.
• It is hoped that this INTERIOR MONOLOGUE
  will reveal the nature of the thought processes
  involved.

                                                    60
 Advantages of observational research

• Experiments can seem highly artificial.
• Observational studies in natural settings
  seem to have more ECOLOGICAL
  VALIDITY.
• Modern advances in technology have
  provided powerful aids to observational
  work. Infra-red photography, for example,
  has contributed enormously to our
  knowledge of nocturnal animal behaviour.
                                          61
              Technology…
• We now know much more about the true habits
  of hyenas, once thought to be cowardly
  scavengers, as they roam the noctural African
  landscape.
• Similarly, CCTV footage has revealed the
  behaviour of packs of human predators as they
  roam a nocturnal urban landscape as
  nightmarish as that envisaged by Anthony
  Burgess in his book Clockwork Orange. His
  dystopic vision has proved to be prophetic.
  Burgess’s creation, Little Alex, who horrified a
  generation, is alive and well today.

                                                     62
     The qualitative approach
• Recent years have seen a resurgence of
  phenomenology in the form of
  QUALITATIVE RESEARCH (Rennie,
  Watson & Monteiro, 2002).
• Buchbinder & Eiskovits (2002), having
  studied the detailed accounts of 20
  women’s experiences of domestic violence,
  concluded that it is primarily shame that
  prevents victims of domestic violence from
  reporting the crime to the police.        63
     Problems with observational
             research
• The observer is not like a video-recorder any
  more than memory is like a filing cabinet.
• Like memory, observation is a highly selective
  process and driven by the assumptions and
  expectations of the observer.
• There are numerous records of eminent
  scientists seeing what they expected to see,
  rather than what was actually there.


                                                   64
   Belief-motivated perception
• Seeing is believing; but believing can also
  lead to seeing and what is seen may not
  actually be there.
• The microscopist Von Hartsoeker, a
  preformationist, believed that he could
  see, in a human spermatozoon, a tiny
  baby in such clarity of detail that he was
  able to draw it.

                                            65
Introspection – or retrospection?
• Arguably, INTROSPECTION is actually
  RETROSPECTION and hindsight can be
  misleading.
• Critics of the ‘thinking aloud’ approach to
  chess have argued that such verbalisation
  not only fails to reveal the true processes
  involved, but may actually alter the
  thinking of the solver.

                                            66
           Instrument reactivity
• The process of any kind of observation, whether in a
  naturalistic or a laboratory setting, can affect the nature
  of what is measured.
• The participant observer who has infiltrated a football
  gang may, in order to conceal his true role and hidden
  agenda, feel forced to influence the social dynamics of
  the group.
• The manner in which he does this may reflect his own
  ideas about the dynamics of group violence.
• The Buchbinder and Eiskovits study raises several
  questions. Is the explanation of the women’s reticence
  really shame, as they say, or something else?
• Did those authors read their own preconceptions into the
  women’s scripts?
                                                           67
             In summary
•  Much psychological research attempts to
   show that some variables exert a causal
   influence over others.
• I reviewed three main strategies:
1. Experimental
2. Correlational
3. Observational
• Each approach has its advantages and
   disadvantages.
                                         68
                 Key terms
• variable
• quantitative versus qualitative variables.
• continuous versus discrete variables.
• measurement, datum, data.
• hypothesis
• experimental, correlation and observational
  research.
• Independent variable, dependent variable.
• scatterplot.

                                                69
               Key terms…
•   correlation
•   correlation versus causation
•   causal model
•   control
•   Stroop interference
•   demonstrations versus experiments
•   rule of one variable
•   extraneous variables, confounding
                                        70
               Key terms …
•   case history
•   participant observation
•   phenomenology
•   introspection
•   interior monologue
•   ecological validity
•   qualitative research

                              71
             Key terms …
• belief-motivated perception
• Instrument reactivity




                                72
Multiple-choice example




                          73
74

				
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