Unformatted text preview: Chapter 2 What Makes Psychological Research Scientific? • Theory – organized system of assumptions and principles that purports to explain certain phenomena and how they are related. o Many theories are tentative, pending more research or accepted by nearly all scientists. (theory of evolution) • Hypothesis – statement that attempts to describe or explain a given behavior. • Operational definitions – precise definition of a term in a hypothesis. Specifies how the phenomena in question are to be observed and measured. • Principle of Falsifiability – predict what will happen as well as what will not. • Confirmation Bias – the tendency to look for or pay attention only to the information that confirms one’s own belief. Descriptive Studies: Establishing the Facts • Studies – select a group of participants to observe, preferably a representative sample (a group of participants that accurately represents the larger population that the researcher is interested in). Accurate representation will yield more accurate results than a large sample size. • Case Studies – also, case history. Detailed description of a particular individual based on careful observation or formal psychological testing. Anything that provides insight into a person’s behavior. • Observational Studies – researcher observes, measures, and records behavior, taking care to avoid intruding on the people or animals being observed. • Test – assessment instruments, procedures for measuring and evaluating personality traits, emotions, aptitudes, interests, abilities, and values. o Objective tests measure beliefs, feelings, or behaviors. o Projective tests are designed to tap unconscious feelings or motives. • Survey – questionnaires and interviews that ask people directly about their experiences, attitudes, or opinions. o Volunteer bias – shortcoming of findings derived from a sample of volunteers instead of a representative sample; those who volunteered may be different from those who did not. • Standardization – whether uniform procedures exist for the giving and scoring of the test. • Norms – established standards of performance. • Reliability – consistency of the scores derived from a test, from one time and place to another. • Validity – the ability of a test to measure what it was designed to measure. Correlational Studies: Looking for Relationships • Measuring the strength of a relationship between two variables. • Positive correlation – high with high, low with low (IQ scores and grades) • Negative correlation – high with low, low with high (dental problems and income) • A correlation does not establish causation. Variables may be associated, but one may not necessarily cause another to occur. Experiments: Hunting for Causes • Independent Variable – a variable that an experimenter manipulates. ...
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- Fall '08
- Psychology, researcher, representative sample, large sample size, formal psychological testing, Psychological Research Scientific