Psychology as a Science

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Psychology as a Science

• Kieran Mc Cartan
• Km62_at_le.ac.uk

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Psychology as a Science What is science?

• Science is based on the assumptions that the
  world is reliable and lawful, and that by careful
  observation relationships between variables
  within the world can be uncovered
• Allport (1947) science has aims of
  understanding, prediction, and control above
  the levels achieved by unaided common sense.
• In order to discover these lawful relationships,
  scientific research relies on careful control,
  manipulation, and measurement of variables.

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Psychology as a Science scientific
characteristics
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Psychology as a Science scientific assumptions

• Realism
• the world exists outside of our perception
• Rationality
• The world is logical and can be understood by
  logical thinking
• Regularity
• The world follows the same laws at all times
• Discoverability
• It is possible to learn how the world works
• Causality
• Every event has a preceding cause

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Psychology as a Science discovering relationships

• There are different types of relationship
  possible between variables
• Causal
• Variable A causes variable B. Changing variable A
  directly causes a change in, or determines the
  value of variable B
• E.g. raising the temperature of a gas will cause
  its volume to increase.
• Correlational
• Changes in variable A are associated with, but do
  not necessarily directly cause changes in
  variable B
• E.g. Intelligence and academic performance.
  Greater intelligence is associated with improved
  academic performance and vice versa, but it is
  possible to have one without the other

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Psychology as a Science

• One popular misconception of psychology is that
  it involves deep and mysterious interpretations
  about human behaviour.
• Psychology seeks to understand behaviour.
  Experimental psychology uses the scientific
  method to do so.
• Using the scientific approach, means that human
  behaviour/nature is assumed to be lawful and
  reliable, and that relationships can be uncovered
  between variables within this area

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Psychology as a Science commonsense claims

• Commonsense claims are often hunches based on
  real evidence e.g. most people would not hurt
  another human being just because an authority
  figure told them too.
• Milgrams (1966) famous experiment into
  conformity.
• Approx 70 of those tested gave electric shocks
  to what they believed was another test subject,
  at a level high enough to kill them.
• Before carrying out the research, Milgram had
  asked other psychologists whether he should go
  ahead with the experiment. He was told that
  nearly all participants would withdraw before
  causing any pain.

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Psychology as a Science scientific research
myths 1

• Science is the collection of facts
• Data is collected facts are not data
• Facts are data interpreted through background
  theory, we construct facts all the time
• E.g. hearing a neighbours music. The sound as
  measured in decibels is the raw data. Your
  judgement of too loud is an interpretation
• Assumptions beyond data are made to explain the
  data
• Facts do not speak for themselves
• In psychological research, data is gathered
  through empirical observation

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Psychology as a Science the empirical method

• In the 19th Century, psychology emerged from
  philosophy to take on a more scientific approach
• Previously techniques such as Introspection were
  used, this was a way of studying human nature and
  the mind from within. Understanding human nature
  was achievable through thought
• As a reaction to some of these subjective
  methods, grew up the objective approach.
  Psychology as an empirical, research based method
• The original empirical method had two stages
• Gathering data objective and without
  preconceptions
• Discover patterns and relationships within the
  data

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Psychology as a Science Inferring theories

• Part of the scientific and empirical method
  involves explaining the data obtained.
• Theory an explanation of patterns and
  relationships seen within collected data
• The theory will give rise to predictions about
  the data that can be put to test
• A hypothesis is a prediction about the data. It
  is a statement of what will happen if the theory
  is correct
• Any theory that cannot be tested through
  hypotheses falls outside the realm of scientific
  enquiry
• E.g. The bus you are waiting for is late. Your
  friend claims that this is because it is raining,
  you claim it is because a new bus company has
  just taken over

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Psychology as a Science Deductive Research

• A top down approach
• GENERAL SPECIFIC
• IF All oranges are fruit
• and all fruit grows on trees
• THEN oranges grow on trees
• Conclusion guaranteed to follow if the evidence
  given is true and the reasoning used to reach the
  conclusion is correct

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Psychology as a Science Inductive Research

• A bottom up approach
• GENERAL SPECIFIC
• Starts with observation (data collection)
• Behavioural patterns and regularities are
  detected from the observations
• Hypotheses are formulated to explore patterns
• Hypotheses used to develop theory
• Iterative process
• Examples
• Grounded theory
• Interviews

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Psychology As a Science Hypothetico-deductive
Research- 1

• Deductive AND inductive
• Test hypotheses based on existing theories
• Interpretations of data provide support for or
  challenge existing theory
• Interpretations of data provide support for or
  challenge existing theory

• Examples
• Experimental
• Interviews
• Scientific psychological research involves
  testing theories through hypotheses.
  Theory-testing also relies on logical
  arguments/deduction

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Psychology As a Science
Hypothetico-deductive Research-2
Perceived problem/idea
CONFIRMATION
GENERAL IDEA
H1 FORMULATION
SPECIFIC PREDICTIONS
Current theory
FALSIFICATION
Inductive conception
Deductive assessment
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Psychology as a Science Theory Testing

• Confirming the hypothesis does not confirm the
  theory
• Other explanations are still possible
• In causal relationships A could cause B or B
  could cause A
• Theories can only be supported by evidence and
  hypotheses being confirmed. It only takes one
  case of the hypothesis not being confirmed to
  disprove the theory
• If hypotheses are disconfirmed, the theory may be
  modified to accommodate new data

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Psychology as a Science scientific research
myths 1

• Science involves dramatic discoveries and
  breakthroughs
• It is actually rare research usually starts from
  current trends and theories
• Research in psychology often replicates or
  extends earlier studies
• Findings are then often used to support or modify
  existing theories
• One finding does not make a breakthrough other
  researchers will query designs, replicate
  findings, which will then lead to further
  modification of theories and so the cycle
  continues

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Psychology as a Science scientific research
myths 2

• Science is all about experiments
• Experiments involve the control and manipulation
  of variables
• Hypotheses can be tested without experiments
• The study of Astronomy in the past could not
  involve experiments, as the necessary technology
  was lacking. Observation was relied upon to test
  theories
• Many hypotheses in psychology are not tested with
  experiments e.g. interviews, observational
  research etc.

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Psychology as a Science scientific research
myths 3

• Scientists have to be unbiased
• The aim is to remove bias from data collection
  and study procedure
• Most researchers are biased about theory may
  interpret ambiguous data to fit own theories
• Mitroff (1974) interviewed a group of scientists
  who agreed that to be a good scientist one had to
  have biases. Researchers must believe in their
  work and their theories
• It is the scientific methods that need to be and
  are unbiased

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Psychology as a Science Approaches/perspectives
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Psychology as a Science Psychological Research

• Psychological research concentrates on human
  behaviour. The focus of the subject matter
  changes according to the type of psychology.
  Research is generally carried out to
• Gather descriptive data e.g. at what age do
  children reach a certain stage of reading
  ability, or attitudes towards a certain
  politician. If the data is numerical in form,
  Descriptive Statistics can be used. If
  qualitative then reports can be written
• Hypothesis Testing much of psychological
  (scientific) research test theories in a
  controlled environment

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Psychology as a Science Hypothesis Testing

• Hypotheses must be specific
• What we expect to happen, stated precisely
• The Null hypothesis is what would happen if our
  theory was incorrect
• If the direction of the result is predicted this
  is a one-tailed hypothesis. If the direction is
  not specified this is a two-tailed prediction
• e.g. there will be a difference in bus departure
  times on rainy versus non-rainy days
• there will be no difference in bus departure
  times on rainy versus non-rainy days
• bus departure times on rainy will be
  significantly later than on non-rainy days

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Psychology as a Science Carrying out Research

• There are many different ways of carrying out
  research, a large number of researchers use a
  controlled method (is strict measurement in data
  gathering).
• Some of the common methods include
• Asking Questions interviews, measuring attitudes
  etc.
• Observational methods
• Experimental Methods (manipulating variables)

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Psychology as a Science Planning Research

• To break down the process of psychological
  research, Coolican (1990) considers four aspects
  of the research
• Variables WHAT shall we study?
• Variables are the things we are interested in
  studying, things we can alter.
• Researcher must consider how to define variables,
  and how to measure them
• e.g. In our theory of the causes of bus lateness,
  the major variable is the weather. Can be defined
  further as rainy vs. non rainy days. How to
  measure this (precise amount of rainfall, or just
  presence of rain)? We might also be interested
  (as this is psychological research) in studying
  the attitudes of those waiting for the bus.
  Again, how to measure?

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Psychology as a Science Planning Research 2

• Design HOW shall we study?
• The design is the overall structure and strategy
  of the research
• Relies on aims of research, which can introduce
  constraints in way the research is carried out.
• e.g. In our example, to measure attitudes of bus
  there are certain practical ways to obtain those
  attitudes (field research)
• The design can also be constrained by resources
  available to the researcher, the nature of
  previous research on the topic, and the
  researchers own attitude towards research methods

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Psychology as a Science Planning Research 3

• Samples WHO shall we study?
• Samples are the people used in the study to
  obtain data (e.g. the people whose attitudes
  towards bus lateness are recorded)
• There are many issues in sampling, one of the
  major ones is that the sample you use must be
  representative of all the individuals that you
  are interested in studying.
• e.g. We are interested in attitudes of all the
  bus users of the particular company. We cannot
  interview them all so we select a representative
  cross-section

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Psychology as a Science Planning Research 4

• Analysis WHAT sort of evidence will we get, in
  what form?
• When we have collected our data, the analysis
  allows us to make sense of what it means
• What analysis is used depends on the design and
  method of measuring variables
• Analysis also depends on the form of data
• Numerical statistical analysis depends on exact
  form of data
• Non numerical analysis often depends on coding,
  and categorising types of responses

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Psychology as a Science Further Reading

• McBurney and White Chapter 1
• Gravetter and Wallnau Chapter 1 (this has more
  of a statistical bent, but still good for an
  introduction to the area)