Scientific Method

Experimental Research An experiment is a scientific investigation that sets out to determine the cause and effect of two or more variables. A “good” experiment… 1. manipulates the independent variable 2. compares the groups in terms of the dependent variable 3. assures that only the IV causes the changes in the DV if this is accomplished then the experiment has internal validity 4. minimizes confounding variables any variable that varies along with the IV 5. uses various types of randomization 6. maintains experimenter control

Independent or Dependent? Independent Variable What the experimenter manipulates The “cause” of the experiment It is “independent” of all other variables Dependent Variable What the experimenter measures The “effect” of the experiment It “depends” on the Independent Variable

Operational Definition A definition of a variable that allows it to be concretely measured. A variable is an Abstract Concept It must be translated into a Concrete Form so it can be measured and studied empirically Helps to successfully communicate ideas to others Often a variety of measures are used

Scientific Method

Physiological Psychology Levels of Investigation Social Individual System Cellular Molecular

Neurological Disorders

Psychological Disorders 10 million people suffer from depression

Scientific Approaches of Physiological Psychology Somatic Intervention alter body (soma) and then record behavior changes Behavioral Intervention alter behavior and then record body (brain) changes Correlation determine the relationship between body measures and behavioral measures