Chapter 1 Psychological Science

Experimentation

Experimentation

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Experiment

 an investigator manipulates one or more factors (independent variables) to observe their effect on some behavior or mental process (the dependent variable)  by random assignment of participants the experiment controls other relevant factors

Theory

 Seeing violence on TV causes children to behave violently in real life.

Hypothesis

 If children watch a violent TV show, they will be more likely to act violently than if children do not watch a violent TV show.

Operational Definitions

 If children watch a violent TV show, they will be more likely to act violently than if children do not watch a violent TV show.

 Children  watch  violent TV show  more likely  act violently  non-violent TV show

Experimental Design

Population 100 children ages 5-8 Random Assignment Experimental Group • 50 children who will watch a violent TV show Control Group • 50 children who will watch a non-violent TV show Independent variable

50 children watch violent TV show • Children will play in a play room for 30 minutes 50 children watch non violent TV show • Children will play in a playroom for 30 minutes Record evidence of violent behavior Record evidence of violent behavior Dependent variable

Experimentation

  Placebo  an inert substance or condition that may be administered instead of a presumed active agent, such as a drug, to see if it triggers the effects believed to characterize the active agent Double-blind Procedure   both the research participants and the research staff are ignorant (blind) about whether the research participants have received the treatment or a placebo commonly used in drug-evaluation studies

Experimentation

 Experimental Condition  the condition of an experiment that exposes participants to the treatment, that is, to one version of the independent variable  Control Condition  the condition of an experiment that contrasts with the experimental treatment  serves as a comparison for evaluating the effect of the treatment

Experimentation

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Random Assignment

 assigning participants to experimental and control conditions by chance  minimizes pre-existing differences between those assigned to the different groups

Experimentation

 Independent Variable  the experimental factor that is manipulated  the variable whose effect is being studied  Dependent Variable  the experimental factor that may change in response to manipulations of the independent variable  in psychology it is usually a behavior or mental process

Experimentation

Design an experiment that would test the effects of alcohol consumption on hand-eye coordination. Be sure to include how your subjects are selected and assigned, the control and experimental conditions, independent and dependent variables, as well as any extraneous or confounding variables.