Scientific method: not prove!!! Confirm or disconfirm!!
Empirical verification: to formulate and hypothesis about human behavior and to test it empirically
- Descriptive statement about behavior that can be confirmed or not.
- A -> causes -> B
- Empirical test: naturalistic observation versus experimentation
Operational definition: to define the term of hypothesis by reference to observable events or
- But, for measuring hypothetical constructs (unobservable cause or factor that determine or
explains several behaviors) we must inferred from observable phenomena (like aggression).
Then test A causes B
Controlled observation: to perform empirical verification under condition in which the phenomenon
under observation can be controlled.
- A causes B: eliminate all possible causes of B except A!!! So eliminate the confounding
variable (C) => the effect of A depends on C = interaction
- 2 ways to control confounding variable:
o Experimental control: in laboratory studies where we can hold the others variables
o Statistical control: in field studies where control is not possible. They measure the
nuisance variable (confounding variable)
Statistical generalization: observation must generalize to conditions other than those under which
they were made. Using empirical confirmation, once the hypothesis has been confirmed, do the
entire procedure again:
- Replication: we should observe the same outcomes
- Extension: rat and after pigeon and chimpanzee etc... The experiment: application of scientific method
- A -> B: measure B
- Manipulate A and observe the effects on B
- Changes in B must co-occur with changes in A (hypothesis confirmed)
Six types of experiments and quasi-experiments:
Name Design problems
One-shot case study: - Don’t know the original mean, nothing to
- Treat group with IV compare
and measure DV X: individuals + - So we are not sure that X causes O
- Education, Freud treatment
One-group tretest-posttest - History: historical that might cause the new
- Measure DV, treat, - Testing: got use to it
Measure DV - Instrumentation: decay other time?
- Maturation: physiological change
- Pretest by treatment interaction: posttest
depends on the pretest and the
Statistic-group comparison: - History, testing, maturation,
- 2 naturally instrumentation are gone!
constituted groups - Selection: naturally => group may have
difference before treatment
- Selection by treatment interaction: maybe
the treatment would not work on the
- Mortality: subjects living groups
True experimental designs:
Name Design Problems
Pretest—posttest control - History, maturation, testing,
group design: instrumentation and interaction of
- randomization: equivalence selection treatment are gone
btn ALL variable (pretest not - Interaction of pretest by treatment on the
necessary) post test result: sensitize subjects to the
nature of manipulation
Solomon (1949) Four-group - Everything gone
design: - 2/4: testing effects
- Randomization - 1/3: treatment interaction
- But, need too much people
Posttest-only control design: - enhance statistical power
- may be generalized to more groups
The factorial experiment: - dv: measure it
factorial experiment: more - iv: observe it
than one treatment applied
to each group Two-factor factorial design:
- 2x3 factorial design:
- Determination of main effect of A (noise), main effect of B (drugs) and the interaction of A
and B (hours of sleep) on the dependent variable
- Read the graphics: not parallel, yes interaction / parallel, no interaction!
Correlational methods: not involve experimentation, just compare and confirming hypotheses
Correlational methods: the study of naturally constituted group, where the IV in the DV vary
continuously and naturally. A -> related to -> B
- Large individual differences among the group members on IV
- Usually done in field with only ONE group of subjects
- Also called ex post facto research, not manipulate IV just measure the DV post facto!
- Matched or paired data and plot them as a scattergram!
- Watch the dots, no slope: A and B are not related, slope: A and B are +/- related, so we need
to quantify the degree of relation = correlation coefficient!
Other non-experimental methods:
- Time series designs: few pre and post test! O O O O O X O O O O O
- But same problem than the pretest-posttest design!
- Introduce a no-treatment control: adding a control group (but often not possible in the field)
- Add and then remove a treatment: O O O X O O O X O O O, if the treatment works take it
away should reverse it!
Theory: definition and evaluation
- Use to describe and explain behavior, they must matched with empirical findings
- Inductive theory: observation of behavior -> induction -> theory of behavior
- Deductive theory: theory -> deduction -> expected behavior (general to particular)
- Operational definitions: observable behavior
Theory evaluation of the goodness of theories: 9 criteria:
Logically consistent: contradiction, A->B, B->C but A not related to C
Verifiable: can generate empirically testable hypotheses!!
Falsifiable: the theory is not false, just she might be disconfirmed
Explains phenomena: explains a lot about the phenomenon
Comprehensive: all human behavior, not just the psychopathological behavior
Parsimonious: simple in terms
Objective: based on empirical facts, independent of personal biases
Dynamic: it can change to accommodate new data (Cronbach’s theory tree ring: different
Skinnerians think that psychology is too young to create theory, they prefer accumulate empirical
data (good prediction of behavior but poor understanding of behavior) Freudian psychoanalytic theory
- Mind = psychic energy system => tension reduction model of the mind
- Instincts are involved in the energy buildup and release: sexual and aggressive instincts
- Pleasure principle: human want to gratify all instinctual desires but society places restrictions
and this causes conflict and tension => leading to coping mechanism and neurosis.
- Freud: behavior is determined only: person + environment= deterministic view
- But we don’t know the determinants because they are carried in the unconscious mind!
Psychoanalysis: theory of personality, a method of therapy, a research technique!
Personality structure: mind has 3 levels of consciousness:
- Conscious: we are aware
- Preconscious: not now aware but can be
- Unconscious: only be aware under special circumstances
Unconscious is a hypothetical construct, cannot be observed but accessible through indirect means:
- Hypnosis, dream, free association, parapraxes (actes manqués), jokes
- Can be demonstrated experimentally: Eagle, Wolitzky, Kline:
o 68% expe group used duck related words
o 50% of control group used duck related words
Structure of the mind:
Id (inherited at birth, totally in the unconscious):
- Source of drive energy: libido or dynamo
- Source of sexual and aggressive instincts
- Operates according to the pleasure principle seeking for release of energy
- Id wants immediate gratification¸ it’s irrational, free of inhibitions
Ego (about 2 years old)
- Develops due to reality constraints: toilet training (loss of freedom)
- Operates according to reality principle, in order to satisfy the id’s demands
- Gratification is delayed
- Operates by secondary process thinking (rational, logical, planful)
- It deals with the self-preservation instincts, mediator btn id (pleasure seeking) and superego
- A partioning of the ego
- Represents: moral functioning, guilt and conscience (social and ethical rules)
- Develops out of the ego due to parental demands (after oedipus complex)
Unreleased libido can lead to anxiety: unacceptable id, impulses, gratified -> tension build up ->
anxiety -> neurosis! But anxiety is cope by ego defense mechanisms (hide id’s wishes from
- Defense mechanisms of the ego: generate by unconscious but conscious expressions: 1. Repression:
- First line of defense unacceptable psychosexual impulses are denied (Oedipus complex)
- Active resistance but no energy released (m