Chapter 12 Quasi-Experimental, Correlational, and Naturalistic Observational 2012 Wadsworth, Cengage Learning

Topics 1.Closed and Open Systems 2.Quasi-Experimental Designs 3.Correlational Procedures 4.Naturalistic Observations

@ 2012 Wadsworth, Cengage Learning Closed and Open Systems

@ 2012 Wadsworth, Cengage Learning Closed and Open Systems Closed system: one in which the important factors that influence the environment are controlled by the experimenter External validity: generalizability of an experimental outcome Open system: one in which the participants are influenced by a number of factors over which experimenters have little control

@ 2012 Wadsworth, Cengage Learning Closed and Open Systems (cont’d.) Figure 12.1 Number of assaults reported in San Francisco before and after the 1989 Loma Prieta earthquake Source: Pennebaker (1991).

@ 2012 Wadsworth, Cengage Learning Closed and Open Systems (cont’d.) Figure 12.2 Percentage of individuals reporting conflict after the 1989 Loma Prieta earthquake Source: Pennebaker (1991).

@ 2012 Wadsworth, Cengage Learning Closed and Open Systems (cont’d.) Figure 12.3 Percentage of individuals reporting dreams about the 1989 Loma Prieta earthquake and the 1991 Persian Gulf War Source: Pennebaker (1991).

@ 2012 Wadsworth, Cengage Learning Closed and Open Systems (cont’d.) Quasi-experimental designs: often used to evaluate the impact of some variable on an ongoing process Correlational designs: attempt to describe the relationship between two variables Naturalistic observation techniques: describe an ongoing process in its natural setting

@ 2012 Wadsworth, Cengage Learning Quasi-Experimental Designs

@ 2012 Wadsworth, Cengage Learning Quasi-Experimental Designs Time series design – Within-subjects design – Useful when we are interested in the effects of an event that has happened to all members of the population that we are studying Single-group pretest-posttest design: involves comparing a single pretest measure with a single post-test measure

@ 2012 Wadsworth, Cengage Learning Figure 12.6 Hypothetical results of a single-group pretest-posttest design studying the effects of relaxation exercises on (a) the total points scored by a gymnastics team and (b) the coach’s estimate of the gymnasts’ composure

@ 2012 Wadsworth, Cengage Learning Quasi-Experimental Designs (cont’d.) Interrupted time series design: involves making several pretest and several posttest measurements Figure 12.7 Interrupted time series design. In this figure, O represents each observation or test score and X represents the occurrence of the phenomenon under study. Note that the phenomenon under study, X, interrupts the periodic measurement of our group of subjects (after Campbell & Stanley, 1963)

@ 2012 Wadsworth, Cengage Learning Figure 12.8 Hypothetical outcomes of an interrupted time series design examining the effects of relaxation exercises on the total points scored by a gymnastics team in 10 weekly meets. X marks the point at which the exercises were introduced. (a) Outcome in which the pretest and posttest scores are fairly consistent. (b) Outcome characterized by much variability in the pretest and posttest scores.

@ 2012 Wadsworth, Cengage Learning Quasi-Experimental Designs (cont’d.) Figure 12.9 Multiple time series design. In the figure, O represents each periodic observation or test score; X represents the occurrence of the phenomenon under study. Note that the phenomenon under study, X, interrupts the periodic measurements of the experimental group but not of the control group (after Campbell & Stanley, 1963)

@ 2012 Wadsworth, Cengage Learning Figure Hypothetical outcomes of a multiple time series design examining the effects of relaxation exercises on the total points scored by a gymnastics team in 10 weekly meets. X marks the point at which the exercises were introduced to the experimental group. (a) Outcome in which the experimental group’s performance improved and the control group’s did not. (b) Outcome in which both groups’ performance temporarily improved

@ 2012 Wadsworth, Cengage Learning Quasi-Experimental Designs (cont’d.) Nonequivalent before-after design – Used when we want to make comparisons between two groups that we strongly suspect may differ in important ways even before the experiment begins – Widely used in educational research

@ 2012 Wadsworth, Cengage Learning Figure Example of a nonequivalent before-after design Source: Adapted from Levitt and Leventhal (1986). Figure Nonequivalent before-after design. In this figure, O 1 and O 2, respectively, represent the pretreatment and posttreatment dependent measures for each group; X represents the treatment or independent variable. Note that for this design, group comparisons are made between the differences in the scores for each group rather than directly between posttreatment scores (after Campbell & Stanley, 1963)

@ 2012 Wadsworth, Cengage Learning Quasi-Experimental Designs (cont’d.) Retrospective and ex post facto designs – Attempt to use empirical procedures for suggesting meaningful relationships between events that have occurred in the past – Weak forms of inference However, can be used to good advantage in the testing of alternative hypotheses (Kerlinger, 1973, 1986)

@ 2012 Wadsworth, Cengage Learning Correlational Procedures

@ 2012 Wadsworth, Cengage Learning Correlational Studies Describe a relationship between two variables However, do not attempt to show how one variable influences the other Correlation coefficient: statistic commonly used for establishing a degree of association A lack of correlation does rule out any possibility of causality

@ 2012 Wadsworth, Cengage Learning Naturalistic Observations

@ 2012 Wadsworth, Cengage Learning Naturalistic Observations Simply paying attention and observing Greatest single application: Darwin’s 5-year voyage on HMS Beagle – Amass descriptive knowledge about a phenomenon – Gain insight about general patterns

@ 2012 Wadsworth, Cengage Learning Concerns While Making Naturalistic Observations Reactive behavior: when a participant’s behavior is influenced by the mere presence of the observer Undetected observations: unobtrusive observations Selective perception: when the observations of untrained observers are markedly influenced by what they expect to see

@ 2012 Wadsworth, Cengage Learning Concerns While Making Naturalistic Observations (cont’d.) Data analysis – Review data several times – Describe the major patterns of behavior – Examine instances of atypical behavior – Evaluate any theoretical ideas you may have recorded – You may get insights about underlying causal factors

@ 2012 Wadsworth, Cengage Learning To Conceal or Not to Conceal; To Participate or Not to Participate Sometimes there is no reasonable way to collect data without being seen – Conceal identity as researchers – Become actively involved in the process Others make no attempt to conceal Decision about whether to be an active participant – Depends on the phenomenon that we are studying

@ 2012 Wadsworth, Cengage Learning To Conceal or Not to Conceal (cont’d.) Deciding whether to remain concealed or to reveal your identity – Depends on whether you are observing highly reactive behaviors – If the behavior of your participants will be different, then use some sort of concealed- observation strategy – If there is much to be gained by personally experiencing, then consider participating

@ 2012 Wadsworth, Cengage Learning Naturalistic Observations (cont’d.) Advantages – Describe behaviors as it naturally occurs – Studies behavioral processes over a period of time Disadvantages – Tend to be qualitative – Representativeness of our sample may be compromised – Do not provide information about how one variable influences another

@ 2012 Wadsworth, Cengage Learning Summary Quasi-experimental designs: set of designs that do not have the necessary controls to rule out important threats to internal validity Correlational designs: focus on describing a relationship between two variables Naturalistic observation: process of observing organisms, usually in their natural environment