This document provides an overview of experimental design. It begins with a brief history, noting that experimental design originated in the 19th century and was advanced by William McCall. It then discusses some issues with experimental design for social sciences, such as complexity and difficulties with observation and replication. The document defines key features of experimental design, including random assignment, control of extraneous variables, manipulation of treatment conditions, outcome measures, group comparisons, and threats to validity. It also discusses random assignment, control, manipulation of conditions, outcome measures, group comparisons, and threats to validity in more depth. Finally, it covers methods of data collection and sampling techniques used in experimental design.

1. EXPERIMENTAL DESIGN
PRESENTED BY STATISTICALLY SIGNIFICANT
SCOTT M. BLANCHARD
ADAM J. HARVEY
MICHAELA P. STONE

2. SAMPLING AND SNACKS
Image source https://en.wikipedia.org/wiki/M%26M%27s

3. HISTORY OF EXPERIMENTAL DESIGN
This form of research began in the 19th century when Schuyler made
the practice common. William A. McCall advanced the notion by
randomly assigning individuals to groups. McCall wrote a book, How
to Experiment in Education that established the procedure we know
today. (Creswell, 2015)

4. ISSUES WITH EXPERIMENTAL DESIGN WHEN
STUDYING SOCIAL SCIENCES
• Complexity of subject matter
• Difficulties in observation
• Difficulties in replication
• Interaction of observer subjects
• Problems of measurement
• Difficulties in control

5. EXPERIMENTAL DESIGN-DEFINING FEATURES &FOCUS
Key Characteristics
• Random assignment
• Control over extraneous variables
• Manipulations of treatment conditions
• Outcome measures
• Group comparisons
• Threats to validity

6. RANDOM ASSIGNMENT
• Definition
• Equating the groups
• Random selection

7. CONTROL OVER EXTRANEOUS VARIABLES
• Extraneous factors
• Pretests
• Posttests
• Covariates
• Matching
• Homogenous samples
• Blocking variables

8. MANIPULATION OF THE TREATMENT CONDITIONS
• Experimental group
• Experimental treatment
• Treatment variables
• Conditions
• Levels
• Interventions

9. OUTCOME MEASURES AND GROUP COMPARISONS
• Outcomes
• Group comparisons definition

10. THREATS TO VALIDITY (SHADISH ET AL, 2002)
• Statistical conclusion validity
• Construct validity
• Internal validity
• External validity

11. METHODS OF DATA COLLECTION
• OBSERVATIONAL STUDY (Techniclly not an experiment, but “causal comparative research”)
• Measures and observes variables without changing existing conditions
• EXPERIMENT
• Assign treatment and observe response
• May use control group
• SIMULATION
• Uses mathematical or computer modeling to replicate a process or situation
• Can be used when it is too expensive, unethical, or impractical to actually test
• SURVEY
• Used to investigate characteristics of a population
• Instrument must be well designed to avoid bias

12. SAMPLING TECHNIQUES
• CENSUS
• Collects data from the entire population
• Impractical due to cost and difficulty
• SAMPLING
• Collects data from portion of the
population
• Must be representative of the population
• Must be sufficiently large
• TYPES OF SAMPLING
• Simple random sampling
• Stratified sampling
• Systemic sampling
• Convenience sampling
• Volunteer sampling

13. EXPERIMENTAL DESIGN ARTICLE REVIEW
Validity and Responsiveness of Concept Map Assessment Scores in Physical Education
Yun Soo Lee, Yongkyu Jang, Minsoo Kang
The purpose of this study was to evaluate the evidence of validity and responsiveness of the concept map
assessment scores in physical education teacher education (PETE).
• Concept Map assessment is an alternative way of assessing teacher candidates’ knowledge structure.
• This research program was based on David Ausubel’s (1968) cognitive psychology theory.
• Cognitive psychology theory –learning takes places by the assimilation of new concepts and propositions into
existing concepts and propositional frameworks held by the learner. (Novak & Cannas, 2008, p. 3)
• Method

15. REFERENCES
Ary, D., Jacobs, L.C., Sorensen, C., & Walker, D.A. (2014). Introduction to research in education
(9th ed.). Belmont, CA: Wadsworth.
Creswell, J. W. (2015). Educational research: Planning, conducting, and evaluating quantitative and
qualitative research (5th ed.). Pearson.
Larson, R., & Farber, E. (2015). Elementary statistics: Picturing the world (6th ed.). Pearson.