Experimental Research DesignBest research methodology to establish cause-and-efect relationship among variablesDependent Variable Independent VariableExperimental or Treatment VariableCriterion or Outcome VariableEssential Characteristics of Experimental ResearchA. Comparison of groups 2 groups (experimentalcontrol grps! experimental group recei"es treatment control group does not recei"e treatmentEssential Characteristics of Experimental Research#. $anipulation of t%e independent "ariable T%e independent "ariable ma& be establis%ed as one form of t%e "ariable "ersus anot%erExample' effecti"eness of classroom teac%ing (it% t%e %elp of blac)board* ppt. * ne( textboo). Essential Characteristics of Experimental Research#. $anipulation of t%e independent "ariable T%e independent "ariable ma& be establis%ed as t%e presence "ersus absence of a particular formExample' effecti"eness of classroom teac%ing+ (%en ne( textboo) is used "s. (%en it is not used.Essential Characteristics of Experimental Research#. $anipulation of t%e independent "ariable T%e independent "ariable ma& be establis%ed as "ar&ing degrees of t%e same formExample' extreme use of ne( textboo) "s. rare use of ne( textboo).Essential Characteristics of Experimental ResearchC. ,andomi-ation .ub/ects are randoml& assigned to groups. ,andom assignment'0 indi"idual participants %a"e t%e c%ance of being assigned to an& of t%e t(o groups0 eliminates extraneous "ariablesTypes of Experimental Designs1. Pre experimental2. True Experimental3. Quasi Experimental4. tatisticalThe One-Shot Case StudyA single group is exposed to treatment and a dependent "ariable is obser"ed (measured! to assess t%e effect of t%e treatment.Eg. To measure t%e effecti"eness of an ad"ertisement for a departmental store+ .%opper1s .top.Unaided Recall Unaided Recall ' 2Do u recall seeing an ad. 3or a departmental store last nig%t4Aided Recall Aided Recall ' 2Do u recall seeing .%opper1s .top ad"ertisement last nig%t4 ! "Treatment "#ser$ation%Depen&ent 'aria#le(T%e One0.%ot Case .tud& Design5ea)ness' ,esearc%er %as no (a& of )no(ing if t%e results obtained at O are due to treatment 6The One-Group Pretest-Posttest DesignA single group is measured or obser"ed before and after t%e treatment.Example' suppose &ou (ant to assess t%e effects of (ee)l& counseling sessions on t%e attitudes of identified bullies in sc%ool."1 ! "2"#ser$ation%Pretest(Treatment "#ser$ation%Posttest(T%e One07roup 8retest08osttest DesignT%e treatment effect is computed as O20O95ea)ness' :ncontrolled extraneous "ariables0 %ence internal "alidit& is ;uestionable. (Example' maturation+ %istor&+ mortalit& etc.!The Static-Group Comparison DesignT(o existing intact (static! groups are usedAlso called nonequivalent control group design2 groups'9.Experimental group(E7!2.Control group(C7!E)*! "1C)*"2T%e .tatic07roup Comparison DesignExample' To test t%e effect of ane( textboo) in increasing interest of students in class. 3ind t(o .tatic groups+ assign t%e ne( textboo) to one class and %a"e t%e ot%er class use t%e regular textboo)+ t%en measure t%e degree of interest in bot% classes at t%e same time.5ea)ness' :ncontrolled0for t%reats to internal "alidit& (Vulnerable to maturit& and location!6 0 treatment#lan) space 0 control ((it% no treatment or (it% a different treatment!O 0 obser"edTrue Experimental Designs The Randomized Pretest-posttest Control Group Design.ub/ects are randoml& assigned to experimental and control groups.True Experimental Designs The Randomized Pretest-Posttest Control Group DesignIn"ol"es t(o groups formed b& random assignment #ot% groups are pretested and posttested$easurements or obser"ations are collected at t%e same time for bot% groupsExample1++ ran&omly selecte& teachersEG:R50 teachersO1Pretest:Faculty Self-Awareness QuestionnaireXance for Peace !rainin"- #or$sho%O&Posttest:Faculty Self-Awareness Questionnaire'G:R50 teachersO(Pretest:Faculty Self-Awareness Questionnaire')o trainin"O*Posttest:Faculty Self-Awareness QuestionnaireT%e ,andomi-ed 8osttest0Onl& Control 7roup DesignT%e Treatment Effect is measured b&(O20O9!0(O