chapter 2 10/27/2013 8:29:00 AM
What Makes Psychological Research Scientific?
Key characterists of the ideal scientist:
organized system of assumptions and principles that purports to explain
phenomena and how they are related
statement that attempts to predict or account for a set of phenomena;
specifies relationships; empirically tested
operational definition: define terms in hypothesis by specifying the
operations & measuring the process or phenomenon
Scientists do not accept ideas on faith or authority
treat conclusions, both old and new, with caution
Caution balanced with openness to new ideas & evidence.
3. Reliance on empirical evidence
Anecdotes are insufficient
Gathered through the use of various research methods.
4. Willingness to make “risky predicitons”
Principle of falsifiability
A scientific theory must make predictions that are specific enough to
disconfirm the theory
Predicts not only what will happen but also what will not happen Confirmation bias
Tendency to seek and accept evidence that supports our theories & ignore
evidence that contradicts beliefs.
explain the source of ideas, how they were tested and what the results were
so replication possible
Peer review process ensures scientific standards and provides system of
checks & balances.
Goal to describe and predict behaviour but does not allow causal
Essential for all studies is obtaining a representative sample
A detailed description of a particular being studied or treated
Most commonly used by clinicians
method where researchers systematically observe & record behavior without
naturalistic observation observations in normal social environment
observations in a more controlled lab setting
Procedures used to measure and evaluate personality traits, emotional
states, aptitudes, interests, abilities, and values
Chacteristics of a good test include
Standardization, reliability, validity
Surveys are questionnaires & interviews that ask people about experiences,
attitudes, or opinions
Allow for extensive data collection but many problems:
Obtaining representative sample (volunteer bias)
Truthfulness of responses
Type and phrasing of questions.
A correlation study is a type of description study that looks for a
relationship between two phenomena
Measure of how strongly two quantifiable characteristics of behavior are
related to one another
Types of Correlations
An association between increases in one variable and increases in another.
An association between increases in one variable and decreases in another.
Stastical measure of correlation (ranges -1.00 to +1.00)
Indicates size and direction of correlation
Often graphed using scatterplots Cautions about Correlations
Are often reported but may be small, nonexistent, or meaningless
They may be misleading
And do not establish causation
Salary and alcoholism in high school teachers
A controlled test of a hypothesis in which the researcher manipulates one
variable to discover its effect on another
An experiment includes:
Variables of interest, control conditions, random assignment, and
consideration of experimenter effects
Variable that experi