Quasi Experimental and single case experimental designs Chapter 11

Program Evaluation Research on programs that are proposed and implemented to achieve some positive effect on a group of people i.e. DARE program evaluation Applies research approaches to evaluate types of programs

Program Evaluation Types Needs assessment Assessment of program theory What problems, if any, need to be addressed? Once identified researchers can plan accordingly Assessment of program theory Used to fix problems found in a needs assessment Involves collaboration of service providers, researchers, clientele, etc… Process evaluation Program monitoring to determine if program is doing what it is supposed to Is the target population being reached? Are the research questions being answered?

Program Evaluation Types Outcome evaluation Impact assessment What did the participants like/dislike about the study? Studying the outcome and then assess the impact of the outcome measure. Efficiency assessment Was the program worth it? Did the benefits outweigh the costs? Uses quasi-experimental designs to assess effectiveness and efficiency

Quasi experimental designs 1 group posttest only design Has no comparison group Doesn’t have good internal validity 1 group pretest-posttest design History Could confound results Maturation People change over time and this could skew results Testing Previous experience could change behavior Instrument decay the deterioration of research instruments or methods during a study

Quasi experimental designs Instrument decay equipment may wear out, respondents may become more casual in recording their responses. Regression toward the mean a.k.a statistical regression The tendency for extreme scores in a distribution to move (regress) toward the mean of the distribution w/ repeated testing. Problem of reliability Occurs when a set of extreme scores collected at one time point is compared to scores taken at another time point.

Quasi experimental designs Nonequivalent control group design A separate control group Selection differences – choosing groups based on naturally existing categories; this is why study is called nonequivalent Nonequivalent control group pretest-posttest design Benefit: a pretest for comparison purposes Interrupted time series design Measurement of dependent variable is interrupted by the quasi independent variable By taking multiple measurements you can look at the effectiveness of a treatment before and after it is introduced. Control series design Extension of the interrupted time series design with a control group

Quasi experimental designs 1 group posttest only design E X O 1 group pretest-posttest design E O X O Nonequivalent control group design C O Nonequivalent control group pretest-posttest design C O O Interrupted time series design E O O O X O O O Control series design C O O O O O O E = experimental group X = treatment C = control group O = observation to collect data

Single case experimental designs A.K.A. Single subject designs or Single participant designs Baseline control period  treatment period The change in behavior during these periods could be attributed to a variety of things Reversal designs To determine if treatment had an effect, revert back to baseline (no treatment) and look at the differences ABA design Baseline control period  treatment period  control period Can also do a ABAB design

Single case experimental designs Multiple baseline designs Observing behavior before and after a manipulation under multiple circumstances Can be done Across subjects Across behaviors Across situations