Research Methods
In Psychology
Defining Psychology
P
Psychology is
defined as the
“scientific study
of mental
processes and
behaviour in
humans” (Grivas
et al (2010; p 4)
Behaviour
Mental
Processes
Walking,
talking,
blinking...
Thinking,
feeling,
learning...
Overt –
directly
observable
Covert –
indirectly
observable
But how can
you study
something
you can’t
see?
Steps in Psychological Research
Identify the
research
problem
Collect
information
and
construction of
the research
hypothesis
Design of the
method
Collection of
the data
Analysis of the
data
Interpretation
of the data
Reporting of
the data
Experimental Research
• Key terms
– Experiment – used to
test the cause-effect
relationship between
variables under
controlled conditions
(p16)
– Independent variable –
the variable that is
deliberately
manipulated, changed or
varied... by the
experimenter in order to
assess its effect.
– Dependent variable –
shows any effects of the
independent variable;
that is, it is the aspect of
a participants
behaviour... that is
measured and is
expected to change as a
result of the
manipulation of the IV
(p17)
Experimental Research
Experimental
Group
IV is
introduced...
Control
Group
IV not
introduced
Is there a
difference
in results?
Measure
effect on DV
Learning Activity: 1.1 REVIEW
P.6 & 1.2 INVESTIGATE P1.2
Measure
effect on DV
Steps in Psychological Research
Identify the
research
problem
Construction of
the research
hypothesis
Design of the
method
Collection of
the data
Analysis of the
data
Interpretation
of the data
Reporting of
the data
The Research Hypothesis
• Key Terms
– Hypothesis – a tentative
and testable prediction
of the relationship
between two or more
events or characteristics.
– Operational Hypothesis
– a hypothesis that
states how the variables
being studied will be
observed and
measured...
•
•
•
•
OH IPOD?
Operationalised IV
Operationalised DV
Population
Prediction of relationship
The Research Hypothesis
A hypothesis...
• Exercise reduces depression
Learning Activity:
INVESTIGATE 1.1 P6.
An operational hypothesis...
• Victorian women aged 2540 who complete 3 hours of
aerobic activity a week will
report fewer incidents of
depression per week than
women who do not
complete the exercise
Steps in Psychological Research
Identify the
research
problem
Construction of
the research
hypothesis
Design of the
method
Collection of
the data
Analysis of the
data
Interpretation
of the data
Reporting of
the data
Extraneous and Confounding variables
Extraneous
Variables
Confounding
Variables
Any variable
other than the
IV that does
cause a change
in the DV
Learning Activity 1.5
Any variable
other than the
IV that may
cause a change
in the DV
There’s a lot to
think about
when planning
an experiment!
Identifying unwanted variables
Experimenter
Effects
Placebo Effect
Order Effects
Demand
Characteristics
Participant
differences
Artificiality
Potential
Variables
Learning Activity 1.6, 1.7 & 1.8
Nonstandardised
conditions
Minimising unwanted variables
Single &
double-blind
procedures
Counterbalancing
Participant
selection &
allocation
Placebos
Eliminating
variables
Standardised
Instructions
Participant Selection
Population – the
larger group from
which the sample is
selected
Convenience Sampling
• Selecting participants who are
readily available
Random Sampling
Sample – a subgroup
of the population
used in the
experiment
Experimental
& Control
Groups
Learning Activity 1.9, 1.10 & 1.11
• Every member of the population
has an equal chance of being
selected.
Stratified Sampling
• Proportions in the population
match proportions in the
sample.
Participant Allocation
Population – the
larger group from
which the sample is
selected
Sample – a subgroup
of the population
used in the
experiment
Experimental
& Control
Groups
Learning Activity 1.12 & 1.13
Random Allocation
• Every member of the
sample has an equal
chance of being selected
for the experimental
group
Counterbalancing - between
Group 1
Group 2
IV alcohol
No IV – no
alcohol
No IV- no
alcohol
IV alcohol
Counterbalancing - within
Group 1
Group 2
IV
No IV
No IV
IV
No IV
IV
IV
No IV
Single and Double-blind
Single-blind procedure...
• ... The participants are not
aware whether they are in
the control or the
experimental groups, so
therefore unaware of the IV.
Double-blind procedures...
• ... The participants and the
researcher/s are unaware of
the conditions that
participants have been
exposed to.
Placebos
• To determine if it is the IV or a
demand characteristic that causes a
change in the DV, we can introduce a
placebo.
IV?
•A placebo is a fake treatment
introduced to a group so they
experience the same demand
characteristics as the experimental
group.
To determine the effect of alcohol
on “having fun” at a party
E2 –
E1 C – no
“fake”
alcohol
alcohol
alcohol
Demand
Characteristics?
Standardised procedures
Experimental
Group
Control
Group
Identical
instructions
Identical
Instructions
Identical
Procedures
Identical
Procedures
Learning Activity 1.14 & 1.15
Experimental Research Designs
Repeated Measures Design
• Each participant takes part in the control group AND experimental group
• Advantage – eliminates participant variables
• Disadvantage – order effects
Matched Participant Design
• Pairs of participants, matched on some characteristic are allocated to each condition
• Advantage – participant differences on important characteristic are reduced
• Disadvantage – other participant variables still exist, time consuming
Independent groups Design
• Each participant is involved in the experimental group OR the control group
• Advantage – large samples, randomly allocated can minimise participant variables
• Cannot eliminate participant variables
E
C
Learning Activity 1.16, 1.17 & 1.18
Steps in Psychological Research
Identify the
research
problem
Construction of
the research
hypothesis
Design of the
method
Collection of
the data
Analysis of the
data
Interpretation
of the data
Reporting of
the data
Data Collection Techniques
Qualitative Data
• Information about the qualities of what
is being measured... descriptions
Quantitative Data
• Information about the quantities of
what is being studied... numbers
Data Collection Techniques
Objective Data
• Data that is directly observable and
measurable.
Subjective Data
• Data that is based on self-reports and
more based on personal opinion.
Learning Activity 1.19
Data Collection Methods
Case Studies
Data
Collection
Self-Reports
•Questionnaires
•Interviews
Learning Activity 1.20, 1.21 & 1.22
Observational
Studies
Steps in Psychological Research
Identify the
research
problem
Construction of
the research
hypothesis
Design of the
method
Collection of
the data
Analysis of the
data
Interpretation
of the data
Reporting of
the data
Analysing Data
Descriptive statistics are used for analysing, organising,
summarising and describing the results. (p64)
Measures
of Central
Tendency
Descriptive
Statistics
• Mean
• Median
• Mode
Tables
Graphs
• Line graphs
• Bar Graphs
• Histograms
• Frequency polygons
• Pie Charts
Steps in Psychological Research
Identify the
research
problem
Construction of
the research
hypothesis
Design of the
method
Collection of
the data
Analysis of the
data
Interpretation
of the data
Reporting of
the data
Interpreting Data
• Inferential Statistics... enable the researcher to draw
inferences, or conclusions based on evidence, about the
results obtained in the study – particularly regarding whether
the results would also occur in the population... (p71)
Sample
How different do
the results have to
be to draw a
conclusion?
E Group C Group
Results
Results
Statistical Significance
A test of statistical significance is used to determine the
extent to which chance has operated and whether this is
an acceptable level (p72)
Statistically Significant
p<0.05
Not Statistically Significant
p>0.05
p<0.05 means less than 5%
probability the results
occurred due to chance
P>0.05 means greater than
a 5% probability the results
are due to chance
What if
p=0.05?
Learning Activity 1.23
Conclusions and Generalisations
Conclusion
• A decision or judgement about what the results
obtained from an investigation mean. (p73)
• Extraneous variables must be considered before
determining if the hypothesis is supported
• A decision or judgement about how widely the
findings can be applied, particularly to other
members of the population... (p73)
Generalisation • Sample MUST be a representative one.
Learning Activity 1.24
A useful checklist...
• To determine if conclusions and generalisations can
be made, an experiment needs to tick all the boxes...
Does the experiment use correct sampling
methods?
Does the experiment use a correct experimental
design that minimises extraneous variables?
Are the results statistically significant?
Steps in Psychological Research
Identify the
research
problem
Construction of
the research
hypothesis
Design of the
method
Collection of
the data
Analysis of the
data
Interpretation
of the data
Reporting of
the data
Reporting Conventions
Title
Abstract
Introduction
Method
Results
Discussion
References
Appendices
Refer to “Writing an Empirical Research Report” sheet
Reliability and Validity
Reliability
• The consistency,
dependability and stability
of the results.
Validity
• The results are an accurate
measure of what they are
supposed to measure.
Learning Activity 1.25 & 1.26
Ethics
Ethics – standards that guide individuals to identify good,
desirable or acceptable conduct. (p77)
Confidentiality
Voluntary
Participation
Deception
What about the
use of animals in
experiments?
Participants
Rights
Withdrawal
Rights
Debriefing
Informed
Consent
Learning Activity 1.27 & 1.28
Chapter Revision
Good luck
• True/False Quiz page 89
• Chapter 1 Test pages 9095