GOALS OF PSYCHOLOGICAL RESEARCH • Focus on observable phenomena, but also study covert processes. • Principle of "determinism”. • Behavior is not "random," but is "determined" by discoverable causes which can be measured. • Conduct sound, well-controlled research in order to understand and predict behavior.
GOALS OF RESEARCH (cont…) • Psychological research strives to Establish cause-effect relationships. • The presumed cause (I.V.) is manipulated by the researcher, and the effect (D.V.) is measured • Extraneous variables • any other variables other than the I.V. which could exert a causal effect on the D.V. • controlled by holding constant across levels of the I.V.
GOALS OF RESEARCH (cont…) • Confounds • Uncontrolled extraneous variables • Left free to vary along with the I.V. • Can't determine whether differences in the D.V. are due to variation of the I.V. or variation of the extraneous variables
When reading the description of a study, ask yourself: • "What variable is manipulated?” • "What variable is measured?” • "What other variables are held constant?" • These will be the "control variables.“ • "Are there variables that were not held constant, but could have affected the DV?" • These are extraneous variables • The variable is a confound if it differs across levels of IV. • Confounds are alternative explanations for effect of IV on DV.
DEVELOPING TESTABLE HYPOTHESES • A testable hypothesis: • specifies a relationship between two or more variables • e.g., Comprehension (DV) is greater when material learned under full attention than under divided attention (IV) • specifies how variables will be measured and/or manipulated (this is an operational definition) • e.g. Comprehension (score on m/c test) will be greater under full attention (single reading task) than divided attention (reading task + tone detection)
Pilot Research • Allows assessment of the adequacy of your operational definitions. • Establishing "Protocols" is important to good research. • written instructions, standardized procedures to follow, and using standardized measuring instruments
Avoiding Biased Research • Inadvertent researcher bias: • ex. Morton (mid 1800s). • If zeitgeist, conclusions not as critically challenged. • Maze bright/dull rats. • “blinds” and placebos
EXPERIMENTAL DILEMMA • An experimenter wanted to test the effects of music on learning by fourth grade children. • (What is a good testable hypothesis?] • Tokeep his work at a manageable level, he decided to introduce music into the classroom every afternoon for one week. No music would be played during the morning hours. The experimenter chose the music carefully‑‑the music was from familiar TV cartoons, and the loudness was moderate. After the week of music presentation, the students were given tests on the morning and afternoon material. Test scores for the morning material were much higher than the scores on the afternoon material. Thus, the experimenter concluded that cartoon music disrupted learning in the classroom. • Do you agree or disagree with this conclusion? In either case tell why.
Fixation of Belief • Nonscientific beliefs about cause-effect relationships • Authority: • taking someone else’s word. • Tenacity: • refuse to alter acquired knowledge even if faced with a counterexample • A priori: • Something that is believed without prior study. “Tends to be taken as a given.”
Science is a method, not a topic!!! • Scientific Method is the best means of fixing beliefs because it is: • Empirical • based on evidence • self-correcting • old beliefs are discarded if new empirical evidence contradicts them
THE NATURE OF SCIENTIFIC EXPLANATION • Induction: reasoning involving going from the "specific" (data) to the "general" (theory) • Induction is often the process involved in "exploratory" research (i.e., early research on a phenomenon).
Deduction: reasoning involving going from the "general" (theory) to the "specific" (data) • Deduction is often involved in later research on a phenomenon • After some data has already been collected and a theory has been formulated to organize existing evidence.
What do predictions reveal? • Popper (1961) • If data confirm a prediction, one cannot say that the theory is true. • If data disconfirms a prediction, one can say that the theory is false. • Problem: • Human nature is to seek confirming, rather than disconfirming evidence.
Strong Inference • Two possible outcomes (hypotheses) are pit against one another in the hopes that one will be eliminated. • If used repeatedly, a best theory should remain.
Theory • A set of proposed constructs (variables) and statements relating the constructs (hypotheses) • Theories are useful in organizing existing data in a way that helps us understand and explain it. • Theories are useful in generating new data via derived hypotheses/predictions from the theory.
Intervening Variables • “Go between" the IV and DV("link" the causal connection) • Unobservable internal processes that help explain the IV-DV causal relationship • e.g., Stereotype Threat ---> Anxiety (the intervening variable) ---> Worse Performance; helps us understand why IV causes DV change. • Sometimes called "mediating variables," because they "carry out" the effect of the IV on the DV • They are often inferred, and are often indirectly measured • Inferring “emotional state” from score on a measure of affect • Inferring level of “distraction” from performance decrement
A “good” theory is… • 1. Parsimonious • the simpler of two competing explanations is to be preferred. Principle called "Occam's razor“. • 2. Precise • specification of concepts and their measurement. • Different investigators must agree about its predictions • 3. Testable • if a theory cannot be falsified through testing, it is of little value. • Often theories make implicit, untestable assumptions
Basic vs. Applied Research • Psychology is concerned with developing general theories/laws of behavior as well as practical applications to solve human problems. • It is important to emphasize the need for both types of research. One type is not "better" than the other • Often difficult to predict a priori, what impact today’s basic research will have 20-30 years from now.