Studying Behavior

Variables Any event, situation, behavior or individual characteristic that varies In our context, the “things” that make up an experiment Must have at least two levels Ex. Age (many levels) Gender (2 levels) Reaction time (many levels)

Variables Quantitative Numeric Age, IQ, weight, speed of presentation of words Qualitative Cannot be quantified numerically Categorical Favorite flavor of ice cream, hair color, gender Quantitative variables vary in amount, qualitative variables vary in kind

VARIABLES Four General Categories Situational variables Temperature, lighting, background noise Response variables Response times, number of errors Participant or subject variables Gender, personality characteristics, age, weight Mediating variables Relationship between depression & cancer

MEDIATING VARIABLE

OPERATIONAL DEFINITIONS OF VARIABLES Variable is an abstract concept that must be translated into concrete forms of observation or manipulation Studied empirically Help communicate ideas to others

RELATIONSHIPS BETWEEN VARIABLES Positive Linear Relationship Increases in one variable relate to increases in another Negative Linear Relationship Increases in one variable relative to decreases in another Curvilinear Relationship Increases in one variable relative to both increases and decreases in another No Relationship Correlation coefficient Relationships and Reduction of Uncertainty

FOUR TYPES OF RELATIONSHIPS BETWEEN VARIABLES

Monotonic vs. Nonmonotonic MonotonicNonmonotonic

Correlation There is individual variability around each of the lines in the graphs Not everyone falls exactly on the line The strength of the relationship between two variables is calculated as a correlation coefficient