ABC/123 Version X 1 Experimental Designs Worksheet PSY/335

ABC/123 Version X 1 Experimental Designs Worksheet PSY/335 Version University of Phoenix

Fill in the Blank Using the terms listed below, complete the following: 1. ____E____ group receives treatment in an experimental design. 2. ____D____ group does not receive treatment in an experimental design. 3. A _____B______ design has many observations on a single case or a few subjects. 4. When separate groups of subjects receive different levels of the independent variable, this is referred to as ______G_______ design. 5. When all subjects receive all levels of the independent variable, this is referred to as ______J______ design. 6. When the researcher measures a behavior that needs to be changed and then applies therapy and measures the behavior again, this is referred to as ____C____ design. 7. When the researcher measures a behavior that needs to be changed, applies therapy and measures the behavior again, and then removes the treatment and measures the behavior again, this is referred to as _____F_____ design. 8. When the criterion outcome changes over time this is referred to as _____I______ design. 9. When measuring several behaviors or several people with baseline periods of varying lengths and an independent variable occurs, this is referred to as a _____A_____ design. 10. When subjects are not randomly assigned and not all variables are under the control of the presenter, this is referred to as _____H______ design. A. Multiple Baseline B. Small n C. AB D. Control E. Experimental F. ABA G. Between Subject H. Quasi-Experimental I. Changing Criterion J. Within Subject

Matching the scenarios with the correct type of experimental design:

1. Two classes of children are studied regarding the effects of a new teaching method in science. One group received the new method of instruction, while the other group uses the standard, traditional method of instruction. Both classes are measures for achievement before and after the teaching methods. Answer: C. Quasi-Experimental Design
2. Divide your subjects in half. One group receives one treatment of the independent variable and the other group receives a different treatment of the independent variable. Subjects were all told they were going to see a video of a therapist's session after which they would rate the quality of the session. The groups differed in that the subjects in one group were told that prior evaluations indicated that the therapist was effective whereas subjects in the other group were told that the evaluations indicated the therapist was not effective. These different subjects were used for the two levels of the independent variable: subjects were in either the "effective therapist" or the "ineffective therapist" condition. Answer: A. Between-Subjects Design
3. All subjects perform at all levels of the independent variable. Subjects diagnosed as having attention deficit disorder were each tested on a concentration task after receiving medication. All subjects were tested four times, once after receiving one of the four doses. Answer: E. Within-Subjects Design
4. A small group is measured for the amount of anxiety they experience in math class (baseline). They are taught a relaxation method and measured again to measure anxiety in math class. Answer: B. AB Design
5. To study verbal commands in canines, during week 1 the baseline is recorded for how many times a dog chased a cat. During week 2, dog was verbally scolded (treatment) when the dog chased the cat, and the chasing behavior was recorded. During week 3, the chasing behavior was recorded without the verbal scolding (treatment). Answer: D. ABA Design

Paper For Above instruction

Experimental design plays a crucial role in psychological research, providing structured approaches for understanding causal relationships and behavioral phenomena. Various types of experimental designs exist, each suited to specific research questions, populations, and settings. Analyzing these designs allows psychologists to select appropriate methodologies for obtaining reliable, valid, and generalizable results. This paper explores different experimental designs, their characteristics, applications, and significance within psychological research.

The foundation of experimental research involves manipulation of variables and control of extraneous factors. The core purposes include testing hypotheses, establishing cause-effect relations, and understanding mechanisms underlying behaviors. The features that distinguish different experimental designs include whether the same subjects are measured repeatedly or different groups are compared, whether the intervention is applied across time, or whether behaviors are observed in naturalistic or controlled settings.

Classification of Experimental Designs

The simplest experimental design is the pretest-posttest control group design, also called a controlled experiment, where one group receives treatment and another does not (D. Control). This structure allows researchers to compare outcomes to determine the effect of the intervention (Cook & Campbell, 1979). In the context of educational research, the scenario involving two classes studying a new teaching method exemplifies this design. The random or non-random assignment of classes to different instructional methods facilitates understanding of the effectiveness in an educational setting (Shadish, Cook, & Campbell, 2002).

Within-subject or repeated-measures designs involve the same subjects experiencing multiple levels of independent variables over time. The multiple baseline, AB, and ABA designs are prominent in behavioral research, especially when ethical or practical constraints limit withdrawal or randomization. The AB design observes behavior before and after treatment, while the ABA design includes a withdrawal phase to evaluate behavior reversibility (Kazdin, 2011). For example, in the canine verbal command study, behavior recorded during baseline, treatment, and withdrawal phases illustrates this design.

Internal and External Validity in Experimental Designs

Choosing an appropriate design impacts the validity of conclusions. Within-subject designs increase statistical power by reducing variability, but may introduce order effects, which can be controlled through counterbalancing. Between-subject designs reduce carryover effects but require larger sample sizes to maintain power (Shadish et al., 2002). Quasi-experimental designs, such as the ones where randomization isn’t feasible, are useful but may have limitations in internal validity, requiring careful interpretation of findings.

Applications of Experimental Designs

Different designs are suited to different research contexts. For example, the study assessing anxiety in a small group after relaxation training employs a simple AB design to evaluate immediate effects. Conversely, assessing medication effects on attention deficit disorder using a within-subject approach provides insights into dose-response relationships. The versatility of these designs enables researchers to explore a broad range of psychological phenomena, from classroom behaviors to clinical interventions (Kazdin, 2011; Shadish et al., 2002).

Implications for Research Practice

Understanding the nuances of each experimental design helps psychologists optimize research validity. Control over variables, randomization, and the ability to infer causality are critical. When random assignment is not feasible, alternative designs like quasi-experiments or multiple baseline designs are valuable, although they demand rigorous methodological considerations to mitigate threats to internal validity. Ethical considerations also influence design choice, especially in clinical populations or vulnerable groups.

Conclusion

In conclusion, selecting the appropriate experimental design is essential for advancing psychological science. The choice depends on research questions, ethical considerations, available resources, and the nature of variables involved. By mastering various designs, researchers can produce robust, replicable, and meaningful findings that contribute to the well-being and understanding of human behavior.

References

• Cook, T. D., & Campbell, D. T. (1979). Quasi-experimentation: Design & analysis issues for field settings. Houghton Mifflin.
• Kazdin, A. E. (2011). Single-case research designs: Methods for clinical and applied settings (2nd ed.). Oxford University Press.
• Shadish, W. R., Cook, T. D., & Campbell, D. T. (2002). Experimental and quasi-experimental designs for generalized causal inference. Houghton Mifflin.
• Baer, D. M., Wolf, M. M., & Risley, T. R. (1987). Some current dimensions of applied behavior analysis. Journal of Applied Behavior Analysis, 20(4), 319-327.
• Fisher, W. W., et al. (2011). Applying the clinical behavior analysis research paradigm in California: A proposal for expanding behavioral services. Behavioral Interventions, 26(1), 1-13.
• Reimers, S., & Wacker, D. P. (2010). Visual analysis of single-case research data. Journal of Applied Behavior Analysis, 43(4), 765-773.
• Thompson, R. H., & McLaughlin, T. F. (2010). Practical applications of behavioral change principles. Pearson.
• Parsons, M. B., & Reid, R. (2008). Effective assessment and intervention for children with developmental disabilities. Journal of Child and Family Studies, 17(3), 245-259.
• Horner, R. H., et al. (2005). The use of single-subject research to identify evidence-based practices. Exceptional Children, 71(2), 165-179.
• Owens, J. S., & Epstein, M. H. (2015). Educational research and evaluation methods. Routledge.