experimental research
DESCRIPTION
Experimental Research. Keith Carrington Valerie Nash Keith Nerby Kathleen Olewinski Tanya Wojciechowicz. ED 740, November 2010. Experimental Research. Purpose : to test cause-and-effect relationships between variables. Experimental Research Groups. - PowerPoint PPT PresentationTRANSCRIPT
Experimental Research
Keith Carrington
Valerie Nash
Keith Nerby
Kathleen Olewinski
Tanya Wojciechowicz
ED 740, November 2010
Experimental Research
Purpose: to test cause-and-effect relationships between variables
Experimental Research Groups
Experimental (Treatment) Group
“participates in an intervention” (p. 226)
experimented on or receives treatment
Control Group “a group that receives no intervention” (p. 226)
NOT experimented on and receives NO treatment
Leedy, P. D., & Ormrod, J. E. (2010). Practical research. Upper Saddle, NJ: Pearson Education.
Experimental Group: receives the treatment or is experimented on
Control Group: receives NO treatment; NOT experimented on
Group 1diet pill
Group 2 placebo
Group 1 Sustained Silent Reading
(SSR)
Group 2 Reading strategy
Experimental Group: receives the treatment or is experimented on
Control Group: receives NO treatment; NOT experimented on
Types of VariablesIndependent Variable
“variable that the researcher studies as a possible cause of something else -- in many cases, it is the one that the researcher directly manipulates” (p. 224)
The variable that is different or changed between groups. This is often the treatment or intervention.
Dependent Variable
“a variable that is potentially influenced by the independent variable… and so to some extent depends on the independent variable” (p. 224)
The variable that is measured or thought to be influenced by the independent variable.
Confounding Variable
Ways that two or more groups are or might be different in addition to the particular treatment or intervention.
When you have more than one independent variable.
Leedy, P. D., & Ormrod, J. E. (2010). Practical research. Upper Saddle, NJ: Pearson Education.
Independent variable: the item the researcher changed between the groups (often it is the treatment)
Dependent variable: variable thought to be influenced by the independent variable (is measured or observed)
Confounding variable: ways the groups might be different in addition to the independent variable
Group 1 diet pill
Group 2placebo
Group 1SSR
Group 2 Reading strategy
Independent variable: the item the researcher changed between the groups (often it is the treatment)
Dependent variable: variable thought to be influenced by the independent variable (is measured or observed)
Confounding variable: ways the groups might be different in addition to the independent variable
Controlling Confounding VariablesPurpose: to maximize internal validity by ruling out confounding variables
•Keep some things constant •Pretest to assess equivalence
•Include a control group •Expose participants to all experimental conditions
•Randomly assign people to groups
•Statistically control for confounding variables
Leedy, Table 10.1 (pp. 243-245)
Leedy, P. D., & Ormrod, J. E. (2010). Practical research. Upper Saddle, NJ: Pearson Education.
Types of Experimental Design1. Pre-Experimental Design: “forming a tentative hypothesis that should be followed up with more controlled studies” (p. 229)2. True Experimental Design: administering different treatments to a single group
3. Quasi-Experimental Design: considers the variables that researchers are unable to control and cannot rule out as alternative explanations for results
Leedy, P. D., & Ormrod, J. E. (2010). Practical research. Upper Saddle, NJ: Pearson Education.
Ex-Post-Facto Design“after the fact”
Purpose: to determine if causality exists
How: the researcher “studies the possible effect of an environmental factor that has occurred prior to the study itself” (p. 228)
Leedy, P. D., & Ormrod, J. E. (2010). Practical research. Upper Saddle, NJ: Pearson Education.
Meta-Analysis
Combines the results of several studies
Experimental Research Issues• Ethics and Integrity• Responsible Conduct• Informed Consent
(e.g., Harmon, 2010)http://www.nytimes.com/2010/04/25/
weekinreview/25harmon.html?_r=1• Human Subjects/
Research Participants• Conflict of Interest• Research Abuses• IRB Approval*• Publication/Peer Review• Collaborative Research
Cardinal Stritch University. (2010). Institutional review board. Retrieved from http://www.stritch.edu/irb.aspx
Experimental Research Collaborations
Benefits Challenges
Broadened experimental approach
Differences in approaches
Interdisciplinary; new knowledge formed
Responsibility and accountability
Development of new research strands
Ethical issues
Expertise, methodology and resources
Conflicts
Grants and other funding opportunities
Disclosing potential conflicts of interest
Heart Monitor ExperimentResearch Question: Do squat jumps change
instantaneous heart rate?
1. Establish and record your resting heart rate using the monitor.
2. If you are in the BLUE group, please remain seated without moving as much as possible. If you are in the ORANGE group, please do as many squat jumps as fast as possible in the time given.
3. Establish and record your heart
rate using the monitor.
Heart Monitor DataHeart Rate
Increased
Heart Rate
Decreased
Heart Rate
Stayed the Same
BlueGroupOrangeGroup
Please identify the following from the heart rate monitor activity.
1. Experimental Group - receives the treatment or is experimented on
2. Control Group - receives NO treatment; NOT experimented on
3. Independent variable - the item the researcher changed between the groups (often it is the treatment)
4. Dependent variable - variable thought to be influenced by the independent variable (is measured or observed)
5. Confounding variable - ways the groups might be different in addition to the independent variable
ReferencesCardinal Stritch University. (2010). Institutional review board.
Retrieved from http://www.stritch.edu/irb.aspx
Harmon, A. (2010, April 24). Where’d you go with my DNA? The
New York Times. Retrieved from http://www.nytimes.com/
2010/04/25/weekinreview/25harmon.html?_r=1
Leedy, P. D., & Ormrod, J. E. (2010). Practical research: Planning
and design (9th ed.). Upper Saddle River, NJ: Pearson
Education.