Experimental Research Presentation


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Experimental Research Presentation

  2. 2. + 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.
  3. 3. +Two ways in which Experimental Research differs from other educational research Researcher 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.
  4. 4. + CHARACTERISTIC of Experimental Research
  5. 5. 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
  6. 6. + 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
  7. 7. + 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.
  8. 8. +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
  9. 9. + MANIPULATION of Independent Variable  The researcher actively manipulates the independent variables MEANS The researcher deliberately and directly determines what forms the independent variable will take and then which group will get which form.
  10. 10. + 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
  11. 11. + 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
  12. 12. + Example of Poor Experimental Design  The one-Shot Case Study  The obvious weakness of this design is : X Treatment (Treatment of Interest) O Observation (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)
  13. 13. + Example of Poor Experimental Design  The One-Group Pretest-Posttest Design X Treatment 10 weeks of counseling O Pretest: 20 item attitude scale completed by students O Posttest: 20 item attitude scale 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
  14. 14. + Example of True Experimental Design  The Randomized Posttest-Only Control Group Design
  15. 15. + Example of True Experimental Design  The Randomized Pretest-Posttest Control Group Design
  16. 16. + 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?