experimental research
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TRANSCRIPT
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Experimental ResearchChapter 13 (page 265)
PREPARED BY• IZZA ATHIRA BINTI AB JALIL• NURUL SYAFIQAH MD AMIN• NUR’IZZAH BINTI MOHAMMED FAUDZAN• NORASYIKIN MT RASHID
+WHAT is Experimental Research? The most conclusive of scientific methods
BECAUSE
The researcher actually establishes different treatments and then studies their EFFECTS, results from this type of research are likely to lead to the most clear-cut interpretations.
+Two ways in which Experimental Research differs from other educational researchResearcher manipulate the independent variable
1. Decide the nature of the treatment
- to whom it is to be applied
- to what extent
2. Enables researchers to go
- beyond description and prediction
- beyond the identification of relationship, to at least a partial determination of what causes them.
+CHARACTERISTIC of Experimental Research
CONCEPT
Experimental group
Control group
Comparison group
Random selection
Random assignment
Independent variable
Dependent variable
Extraneous variable
DEFINITION
The group that received a treatment of some sort in an experiment
The group that does not receive a treatment in an experiment
The group that receives a different treatment
A process wherein every member of a population has an equal chance to be a member of the sample
Every individual who is participating in an experiment has an equal chance of being assigned to any of the experimental or control conditions being compared
Researcher chooses to study in order to assess their possible effect(s) on one or more other variables
Refers to the result(s) or outcome(s) being studied
Independent variables that have not been controlled
+PURPOSE of Experimental Research
To establish cause and effect relationship among variables
The only type of research that directly attempts to influence a particular variables
Correlational studies may demonstrate a strong relationship between socio-economic level and academic achievement, for instance
+BASIC STEPS in conducting an experiment
Formal experiment consist of two conditions :
At least two conditions or methods are compared to assess the effect(s) of particular conditions The independent variable is directly manipulated by the researcher.
+Various Threats to Internal Validity Associated with Different Experimental Design
Holding certain variables constant
Building the variable into the design
Matching
Using subjects as their own controls
+MANIPULATION of Independent Variable
The researcher actively manipulates the independent variables
MEANSThe researcher deliberately and directly determines what forms the independent variable will take and then which group will get which form.
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THREE WAYS in such the manipulation can occur
1. One form of variable versus another
E.g. : Comparing the inquiry method with the lecture method of instruction in teaching chemistry
2. Presence versus absence of a particular form
E.g. : Comparing the use of power point slides versus no power point slide in teaching statistic
3. Varying degrees of the same form
E.g. : Comparing the effects of different specified amounts of teacher enthusiasm on student attitudes towards mathematics
+Group Design in Experimental Research Good designs control many of the various threats to
internal validity (chapter 9) while poor designs control only a few.
The quality of an experiment depends on how well the various threats to internal validity are controlled.
The essential ingredient of a true experimental design is that subjects are randomly assigned to treatment groups.
Random assignment is a powerful technique for controlling the subject characteristics threat to internal validity
+Example of Poor Experimental Design
The one-Shot Case Study
The obvious weakness of this design is :
XTreatment
(Treatment of Interest)
OObservation
(Dependent variable)
- absence of any control
- does not provide for any comparison
- no way of knowing if the result obtained at O
are due to treatment (X)
+Example of Poor Experimental Design
The One-Group Pretest-Posttest Design
XTreatment10 weeks
of counseling
OPretest:
20 item attitude scale completed
by students
OPosttest:
20 item attitudescale completed
by students
Better than one-shot case study because researcher at least know whether any changes occurred
Threats to internal validity exist and may influence the outcome of the study
+Example of True Experimental Design
The Randomized Posttest-Only Control Group Design
+Example of True Experimental Design
The Randomized Pretest-Posttest Control Group Design
+QUESTIONS :
1. Why experimental research is different than any other educational research?
2. What is the purpose of experimental research?
3. Describe the basic steps involved in conducting an experimental research?
4. What is one of experimental research characteristic?
5. Explain how to identify poor experimental design?