Course: PSYC*1000 (DE)
Professor: Harvey Marmurek
Schedule: Summer, 2012
Textbook: Psychology – Tenth Edition in Modules authored by David G. Myers
Textbook ISBN: 9781464102615
Module 03: Research Strategies: How Psychologists Ask and Answer Questions
How do theories advance psychological science?
• Theory, hypothesis, operational definitions, replication
• Theories lead to hypotheses which leads to research observations which can confirm, reject or revise our
• Theory will be useful if it (1) organizes a range of self-reports and observations, and (2) implies predictions
that anyone can use to check the theory or to derive practical applications.
Theory: an explanation using an integrated set of principles that organizes observations and predicts behaviours or
Hypothesis: a testable prediction often implied by a theory.
Operational Definition: a statement of the procedures (operations) used to define research variables. For example,
human intelligence may be operationally defined as “what an intelligence test measures.”
Replication: repeating the essence of a research study, usually with different participants in different situations, to
see whether the basic finding extends to other participants and circumstances.
The Scientific Method: a self-correcting process for asking questions and observing answers.
How do psychologists use case studies, naturalistic observation, and surveys to observe and describe
behaviour, and why is random sampling important?
• Case studies examine one individual in depth. Individual cases can suggest fruitful ideas. But to discern the
general truths that cover individual cases, we must answer questions with other research methods.
• Naturalistic Observation records behaviour in natural environments; does not explain behaviour but
describes it. Offers interesting snapshots of everyday life, but it does so without controlling for all the
factors that may influence behaviour. It’s one thing to observe the pace of life in various places, but another
to understand what makes some people walk faster than others.
• Survey looks at cases in less depth. Best basis for generalizing is from a representative sample. Before
accepting survey findings, think critically: Consider the sample. You cannot compensate for an
unrepresentative sample by simply adding more people.
o Wording effects
o Random sampling
Case Studies: an observation technique in which one person is studied in depth in he hope of revealing universal
Naturalistic Observation: observing and recording behaviour in naturally occurring situations without trying to
manipulate and control the situation.
Survey: a technique for ascertaining the self-reported attitudes and behaviours of a particular group, usually by
questioning a representative, random sample of the group.
Population: all the cases in a group being studied, from which samples may be drawn.
Random Sample: a sample that fairly represents a population because each member has an equal chance of
inclusion. What are positive and negative correlations, and why do they enable prediction but not cause-effect
• Correlation – one trait or behaviour is related to another
• Negative correlation – one set of scores is going up and the other set of scores is going down
• A correlation coefficient helps us see the world more clearly by revealing the extent to which two things
• Association does not prove causation. Correlation indicates the possibility of a cause-effect relationship but
does not prove such.
Correlation: a measure of the extent to which two factors vary together, and thus of how well either factor predicts
Correlation Coefficient: a statistical index of the relationship between two things (from –1 to +1)
Scatterplot: a graphed cluster of dots, each of which represents the values of two variables. The slope of the points
suggests the direction of the relationship between the two variables. The amount of scatter suggests the strength of
the correlation (little scatter indicates high correlation).
What are the characteristics of experimentation that make it possible to isolate cause and effect?
• Experiments enable researchers to isolate the effects of one or more factors by (1) manipulating the factors
of interest and (2) holding constant (“controlling”) other factors. Often create an experimental group and a
control group, randomly assigning people to the two conditions.
• Unlike correlational studies, which uncover naturally occurring relationships, an experiment manipulates a
factor to determine its effect.
• A variable is anything that can vary. Experiments aim to manipulate an independent variable, measure a
dependent variable, and allow random assignment to control all other variables. An experiment has at least
two different conditions: an experimental condition and a comparison or control condition. Random
assignment works to equate the groups before any treatment effects occur.
Experiment: a research method in which an investigator manipulates one or more factors (independent variables) to
observe the effect on some behaviour or mental process (the dependent variable). By random assignment of
participants, the experimenter aims to control other relevant factors.
Experimental Group: in an experiment, the group that is exposed to the treatment, that is, to one version of the
Control Group: in an experiment, the group that is not exposed to the treatment; contrasts with the experimental
group and serves as a comparison for evaluating the effect of the treatment.
Random Assignment: assigning participants to experimental and control groups by chance, thus minimizing pre-
existing differences between those assigned to the different groups.
Double-Blind Procedure: an experimental procedure in which both the research participants and the research staff
are ignorant (blind) about whether the research participants have received the treatment or a placebo. Commonly
used in drug-evaluation studies.
Placebo Effect: experimental results caused by expectations alone; any effect on behaviour caused by the
administration of an inert substance or condition, which the recipient assumes is an active agent.
Independent Variable: the experimental factor that is manipulated; the variable whose effect is being studied.
Confounding Variable: a factor other than the independent variable that might produce an effect in an experiment.
Dependent Variable: the outcome factor; the variable that may change in response to manipulations of the
independent variable. Research Method Basic Purpose How Conducted What is Manipulated Weaknesses
Do case studies, No control or
To observe and record naturalistic variables; single
behaviour observations, or cases may be