UNIT 5 - EXPERIMENTAL DESIGN AND CONTROL for students - KIN 332 Research Design and Statistics Experimental Design and Control 1 Experimental

UNIT 5 - EXPERIMENTAL DESIGN AND CONTROL for students -...

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Research Design and Statistics Experimental Design and Control 1 KIN 332
Study design Refers to the structure of the experiment Developed a prioriIdentifying different groups and grouping assignments Example: Randomly assign healthy males and females to a training group or control 2 Experimental Control
Independent variable (X) Refers to a variable that is manipulated or under the control of the researcher Treatment variable Example: 6 week strength training study with 2 groups (experimental and control) Training is the independent variable 3 Experimental Control
Dependant variable (Y) Refers to the measured variable The value of the dependant variable “depends” on the independent variable Example: Strength (Nm) is the dependant variable that will be determined if the participants train or not 4 Experimental Control
Extraneous variable Refers to a variable “outside” of your studyExample: Strength training study Person assigned to the control group enrolled in a personal fitness class for credit 5 Experimental Control
Intervening variable Refers to a variable “inside” your study that will affect the dependant variable This variable is a result of the independent variable Example: Strength training study Person assigned to the training group may start walking more or running because their quadriceps feel stronger 6 Experimental Control
Random assignment The process of assigning participants to groups Each participant has an equal chance of being assigned to any group Should remove rater bias and “balance” the groupsFlipping a coin, sampling without replacement 7 Experimental Control
Control groups Refers to a group to which the experimental group is compared Forms a basis for comparison “Unethical” to not include a control group in your study when reasonably possible Usually a group that is not exposed to the treatment or does not have a condition 8 Experimental Control
Masking (blinding) Process in which the experimenter and / or the participant are unaware of the treatment Attempts to remove conscious and unconscious bias of both parties 9 Experimental Control
Double masked design The experimenter and participant are unaware of the treatment Participants do know that they may receive one treatment or the other Example: Creatine supplementation on strength One group ingests a non-creatine supplement that looks, tastes and is packaged the same as the real creatine supplement 10 Experimental Control
Controlling for participant differences Random assignment Creates a balanced distribution Differences between groups is a result of “chance”Equality will occur in the long run Equality will more likely occur in studies with large sample sizes 11 Experimental Control