DV – measured Aggression
Benefit of random assignment: * The participants who wore black t-shirts and white t-shirts were equal on all other factors except the color they were wearing * People who are naturally aggressive have an equal chance of being in each group
Which of the following types of studies allows researchers to draw causal conclusions?
C) Experimental
Hypotheses are used to test theories. A) True
-Theories explain many different observations and they explain the causal relationships that we expect exist.
-A hypothesis is derived from a theory and is very specific.
Operational Definitions are important! * Some constructs are easier to define than others * What does it mean “to wear black clothes”? * What do we mean by “aggression”? * convert an abstract concept into a NUMBER
VALIDITY!
The idea of how much your operational definition actually overlaps with what you are trying to measure.
Experimental Research – Interpreting Results Dating study(NB)
Interaction: when the effect of one IV on the DV depends on the value (or level) of the other IV
Main Effect: When an IV has an effect of similar magnitude and direction across levels of the other IV
Ethics of Experimental Research * institutional review boards * informed consent * use deception only if essential * protect people from harm * information about participants should remain confidential * debrief participants at end
Methods – summary * independent variable (IV) is something that is manipulated * dependent variable (DV) is something that is measured * Correlational studies can determine variables that are related, but cannot determine that one variable CAUSES another * Experimental lab studies can, however, determine causation
Remember James! James represents the typical case He is an average Represents our best