Determinants of using experimental groups and choosing reasons in psychological researches

Abstract

Until The Second Half Of Nineteenth Century , Psychology Depended On Philosophy In Its Experiences Which Means It Depend On Individuals Feelings Toward Psychological Experiences And Rapid Observation . As For The Scientific Organized Experimentation And Observation By Machines Have Been Used Later .The Experimentation Looking For The Cause Of Phenomena And How Is That Happened Also Reveal The Causal Relationship Between Among Phenomena . The Experiences In Psychology Field Include In Its Simplest Form Only One Variable ( Effective) Which Is Called Independent Variable As Well As Another Variable ( Affected ) That Called Dependent Variable .So To Conduct Any Experiment In Psychology We Need To A Sample And This Sample Should Be Represent The Studied Society That Mean We Can Generalize The Results Of The Study On Society As A Whole . Choosing Groups In Experimental Researches Is Considered The First Step In Experiences Success . So The Researcher Will Focus On Displaying The Types Of These Groups And How To Design The Psychological Experiences With Their Advantage And Disadvantage.