Presentation on theme: "The Science of Psychology The Scientific Method and Research Design."— Presentation transcript:
The Science of Psychology The Scientific Method and Research Design
Experimental Research With experimental research, one can determine cause and effect among variables. Experiments allow researchers to manipulate or control one variable to observe the effect of that manipulation on another variable, while holding all other variables constant.
More on Experimental Research There are several terms you need to memorize regarding experimental research.
Hypothesis A statement about the relationship between two or more variables Must be testable
Key Terms - Variables Variables- Factors that change in an experiment Independent Variable (IV)- The factor that the experimenter manipulates or changes Dependent Variable (DV)- The factor being measured Extraneous or Confounding Variable- An undesirable variable that influences the relationship between the IV and DV, though it is not the variable of interest. These variables are undesirable because they ADD ERROR to an experiment. A major goal in research design is to decrease or control the influence of extraneous variables as much as possible. Ex post facto – Research in which we choose subjects based on a pre-existing condition.
Key Terms – People Involved Subjects- Animals or humans used in your study Participants- Humans used in your study Confederate – Someone who is in on the experiment but pretends to know nothing about it Population- The large group containing all potential participants for your study (can be defined in many ways) Sample- Small subgroup of participants chosen from the larger population
Key Terms – People Involved Experimental Group- The group that experiences the IV; OR the group on which the critical part of the experiment is performed Control Group- The group that does not experience the IV; OR the group that does not participate in the critical part of the experiment
Key Terms - Locations Lab setting- Gives the researcher greater control over variables, but may not be a perfect replication of the real-world environment Field setting- Gives a more natural look at the participants because they are in their natural habitat, but the researcher has less control
Key Terms – Control Measures Single-Blind: subject unaware of assignment Double-Blind: subject and experimenter unaware of placement Randomization Random Sampling To randomly select participants from population Allows you to generalize results Random assignment To randomly divide participants into groups Either the _____________ or _____________ group