PSY 302: Part 1—Page 1 of 8
PSY 302: Experimental Psychology
Part 1: Chapters 1, 2, 3, and 4
http://courses.MissouriState.edu/JRosenkoetter/
Chapter 1: Explaining Behavior, pp. 1-31
I.
“Psychology is the science of behavior and mental processes” (Bordens &
Abbott, 2014, p. 7).
II.
Science is a way of thinking, an attitude, or a philosophy.
III.
Types of scientific research
A. Basic
B. Applied
IV.
Explaining behavior
A. Scientific explanations:
1. empirical
a)
based on evidence from the senses
b)
objective (observable)
c)
verifiable by others
2. rational
3. testable
4. parsimonious (law of parsimony, Ockham's razor, Lloyd
Morgan's canon)
5. general
6. tentative
7. rigorously evaluated
B. Commonsense explanations:
1. from observation of the real world
2. not rigorously evaluated
C. Belief-based explanations:
1. come from a trusted source
2. accepted on faith (assumed to be true)
3. no evidence is required
4. often post hoc (after-the-fact)
5. not limited to the realm of what can be observed and verified
V.
Problems
A. Faulty inference
B. Pseudoexplanations:
1. circular explanation (tautology) that is just another label for the
same behavior Fig 1-1 no independent measures
PSY 302: Part 1—Page 2 of 8
VI.
Knowledge can be acquired by using
A. The method of authority (There could be a problem with bias.)
B. The rational method
1. René Descartes (1596-1650)
2. skepticism
3. follows rules of logic
4. consistent with known facts
C. The scientific method
1. observe behavior
2. identify variables (Variables are any measurable conditions,
events, characteristics, or quantities that can take on two or more
values.)
3. formulate an hypothesis about the relationship between
variables
4. observe more
5. refine
6. retest Fig 1-3
For your first experiment, please rate each of the 20 diagrams using a 7-point
equal-interval scale ranging from 1 (do not like the diagram at all) to 7 (like the
diagram very much).
Chapter 2:
Developing and Evaluating Theories of Behavior, pp. 32-55
I.
Scientific theories
A. Definition:
1. A scientific theory is “a plausible or scientifically acceptable,
well-substantiated explanation of some aspect of the natural world;
an organized system of accepted knowledge that applies in a
variety of circumstances to explain a specific set of phenomena
and predict the characteristics of as yet unobserved phenomena”
(Bordens & Abbott, 2014, p. 33).
2. It is an explanation of some aspect of the natural world.
3. Only observable and confirmable phenomena fall within the
sphere of a scientific theory.
4. A theory is plausible or scientifically acceptable if the
explanation follows logically from reasonable assumptions, given
our current state of knowledge.
B. Theory versus hypothesis
1. A hypothesis is “a tentative explanations for an observation,
phenomenon, or scientific problem that can be tested by further
investigation” (Bordens & Abbott, 2014, p. 33).
2. Hypotheses are simpler than theories.
PSY 302: Part 1—Page 3 of 8
3. Predictions are simpler than hypotheses; they do not include an
explanation.
C. Theory versus law: a theory that has been substantially verified is
sometimes called a law.
D. Theory versus model: a model refers to a specific implementation of a
more general theoretical view.
E. Computer modeling
F. Mechanistic versus functional explanations
1. Mechanistic explanations tell how a system works without
telling why it does that it does.
2. Functional explanations refer to the purpose or goal of a given
attribute or system without describing how those purposes of goals
are achieved.
II.
Types of theories
A. Quantitative versus qualitative
1. A quantitative theory is expressed in mathematical terms.
For example, in 1943, Clark Hull’s theory was
sEr = sHr x D – Ir – Or
That means momentary effective reaction potential equals habit strength times
drive minus inhibition minus oscillation, which is responsible for variability in
behavior.
2. A qualitative theory is not expressed in mathematical terms.
B. Level of description
1. descriptive theories, e.g., Yerkes-Dodson relationship between
arousal and performance
2. analogical theories, e.g., Konrad Lorenz’s psycho-hydraulic
model of motivation Fig 2-1
3. fundamental theories, e.g., cognitive dissonance theory
C. Domain (or scope) of a theory
III.
Roles of theory in science
A. Understanding
B. Prediction
C. Organizing and interpreting research results
D. Generating research: The heuristic value of a theory is its ability to
provide ideas for new research.
IV.
Characteristics of a good theory
A. ability to account for data within its domain
B. explanatory relevance
C. testability
D. prediction of novel events within its domain
E. parsimony
PSY 302: Part 1—Page 4 of 8
V.
Strategies for testing theories
A. Confirmation strategy: If the relationships predicted by a theory are
observed in empirical data, then your theory has been supported. It does
not mean that the theory has been proven to be correct. There is no
logical way to prove a theory correct.
B. Disconfirmation strategy: If A is true (the theory is correct), then B will
not be true (a certain outcome will not occur); thus, if B is true (the
outcome does occur), then A is false (the theory is erroneous).
C. Using confirmation and disconfirmation strategies together
1. Confirmation strategies used first to find support
2. Then use disconfirmation strategy for all of the possible
alternative explanations.
3. After eliminating competing alternatives, you have only one
remaining, that process is called strong inference.
IX.
Theory-driven versus data-driven research
Chapter 3
Getting Ideas for Research, pp. 56-98
I. Sources of Research Ideas
A. Unsystematic observations
1. casual or haphazard
2. needs to be transformed into something that can be tested
empirically
B. Systematic observation
1. carefully planned observation of behavior under natural
conditions
2. read published research reports of behavior
3. your own previous research can be a source
4. research projects being run on the Internet
C.
Theory--a set of assumptions about the causes of behavior and
rules that specify how the causes act.
D.
a need to solve practical problems—applied research
II. Developing Research Questions
A. Ask questions that are answerable. Narrow the topic into a testable
hypothesis by:
1. asking an empirical question
a)
it can be answered through objective observation
b)
using evidence from senses
c)
is verifiable
d)
is reproducible
PSY 302: Part 1—Page 5 of 8
2. A variable needs an operational definition (a definition that
precisely describes the actions or operations that will be made to
measure or control the variable), for example (e.g.), the dependent
variable is how the participant rated each of the 20 diagrams using
a 7-point, equal-interval scale ranging from 1 (do not like the
diagram at all) to 7 (like the diagram very much).
B. Ask important questions
1. the answer will clarify relations among variables
2. the answer will show which of several competing hypotheses is
supported
3. the answer leads to a practical application
C. Unimportant questions:
1. the answer is already well known
2. the variables that are studied have small effects and are of no
theoretical interest
3. there is no reason to believe that there is any relationship
among the variables
III.
Reason for reviewing the literature
A.
to find what has already been done
B.
to help you design your study
C.
to find other hypotheses
IV.
Sources of research information
A.
primary--full research report
B.
secondary source--a summary of the research report
C.
If you use a secondary source, cite only the secondary source in
your literature review and reference page
D.
books
E.
scholarly journals
1.
refereed (or peer reviewed)
2.
nonrefereed
F.
conventions
G.
personal communications
H.
technical reports
I.
Dissertation Abstracts International
J.
the Internet
K.
Psychological Abstracts
L.
Thesaurus of Psychological Index Terms
M.
Science Citations Index
N.
Social Science Citations Index
O.
Index Medicus
P.
Index to Scientific Reviews
Q.
Reader's Guide to Periodicals
R.
Annual Review of Psychology
PSY 302: Part 1—Page 6 of 8
V.
Performing library research
http://libraries.missouristate.edu/subject.htm
APA also has more on PsycINFO at:
http://www.apa.org/pubs/databases/psycinfo/index.aspx
Guide to the Fields in APA Database Records
http://www.apa.org/pubs/databases/training/field-guide.aspx
APA Style Help
http://www.apastyle.org/apa-style-help.aspx
PsycARTICLES—full text journal articles on-line
http://www.apa.org/pubs/databases/psycarticles/index.aspx
VI.
Research report
A.
Abstract
B.
Introduction
C.
Method
Participants (or subjects)
Apparatus (or materials)
Procedure
D.
Results
E.
Discussion
F.
References
VII.
Factors affecting the quality of a source of research information
A.
Publication practices Fig 3-6
B.
Statistical significance
C.
Consistency with previous knowledge
D.
Significance of the contribution
E.
Editorial policy
F.
Peer review
G.
Values reflected in research
VIII.
Developing hypotheses
Chapter 4
Choosing a Research Design, pp. 99-122
I. Functions of a design
A. Describe and classify
B. Test hypotheses
PSY 302: Part 1—Page 7 of 8
II. Experimental research
A. Done to show causal (cause-and-effect) relationships
B. A relationship is causal if changes in one variable produce changes in
another variable.
C. Experimental designs:
1. manipulation of an independent variable
2. control over extraneous variables
D. Independent variable
1. has several levels or treatments
2. levels are chosen and set by the experimenter
E. The behavior that is observed and recorded is called the dependent
variable.
F. If a causal relationship exists, the value of the dependent variable
depends upon the level of the independent variable (or treatment) to
which the subject was exposed.
G. An experimental group receives the treatment and a control group
does not.
H. Extraneous variables are any variables that you are not interested in
studying.
I. Control them by
1. holding them constant (the same)
2. randomize their effects across the levels of the independent
variable
a) distributes their effects evenly
b) inferential statistics requires a random sample, page 432,
assumption 1
J. Experiments allow cause-and-effect relationships to be noticed, but
this design may not always be used.
1. variables may be impossible to manipulate
2. variables may be unethical to manipulate
3. tight control of extraneous variables may limit the generality of
the results
III. Demonstration
A. Only one level of the treatment is used (no true independent variable)
B. This can show what happens, but it cannot show a causal relationship.
IV. Correlational research
A. Determines whether variables covary
B. Do not manipulate an independent variable
C. Do not (or cannot) randomly assign subjects to groups, e.g., women
and men
D. Correlational research cannot confirm causation.
PSY 302: Part 1—Page 8 of 8
E. Measure two (or more) variables and determine whether they covary.
Both variables could be called dependent variables.
1. Pearson product-moment correlation coefficient; two variables
measured on an interval scale, pp. 413-415
2. point-biserial correlation; one interval variable and one nominal
variable, p. 416
3. Spearman rank order correlation; two ordinal variables, p. 416
4. phi (Φ) coefficient, two nominal variables, p. 416
F. If a reliable relationship (correlation) exists, you can use one variable
(X) to predict the other variable (Y).
predictor (X) --> criterion (Y)
attendance --> grade
G. Third-variable problem (an unobserved and unmeasured variable)
If you can measure the correlation between a “third variable” and
the two that you want to study, you can control the effect of the
third variable with statistics. (See partial and part correlation, pp.
470-472.)
H. The directionality problem: Which variable is the predictor?
I. Why use correlational designs?
1. At the start, you may just want to describe relationships, later
you may want to know the causes. Fig 4-2
2. When it would be impossible or unethical to manipulate
variables.
3. To see how variables operate in the “real world.”
V. Internal and External Validity
A. Internal validity: The ability of a design to test the hypotheses (or
predictions) and eliminate rival hypotheses.
B. Confounded variables are variables that are not separated, for
example, Pepsi and “M” versus Coke and “Q.”
C. External validity: How well the conclusions can be generalized to other
samples or settings.
VI. Two research settings:
A. Laboratory
1. have control of variables
2. have artificiality
3. can simulate the real world in the laboratory
B. Field setting
1. natural environment
2. poor internal validity (poor control of variables)
3. good external validity (already in a real world setting)