Chapter 4 – Studying Behavior
•Variable – an event, situation, behavior, or individual characteristic that varies
(ie. Word length, gender, age).
•Each of these variables represents a general class within which specific instances
will vary. The specific instances of these is called the levels or values of the
variables. A variable must have two or more levels or values.
•Some variables will have numeric values – hence they will be quantitative (ie.
Age, your IQ). They differ in amount or quantity. Algebra can be applied to such
variables (ie. Mesure the mean).
•Some variables are not numeric and instead identify categories – hence they are
categorical (ie. Gender, occupation). These variables differ, but not by quantity, and
algebra cannot be applied to them.
•Variables can be classified in four general categories
1.Situational variables describe characteristics of a situation or environment
(ie. The spatial density of a classroom, the credibility of a person who is
trying to persuade you).
2.Response variables are the responses or behaviors of individuals (ie.
Reaction time, performance on a cognitive task).
3.Participant or Subject variables are characteristic differences of the
individuals (ie. Age, gender, intelligence, personality traits).
4.Mediating variables are psychological processes that mediate the effects
of a situational variable on a particular response (ie helping is less likely
when there are more bystanders to an emergency…the mediating variable
is diffusion of responsibility).
Operational Definitions of Variables
•A variable is an abstract concept that must be translated into concrete forms of
observation or manipulation, thus a variable such as “aggression” must be defined
in terms of the specific method used to measure or manipulate it.
•Operational definition – a definition of a variable in terms of the operations or
techniques the researcher used to measure or manipulate it.
•Variables must be operationally defined so they can be studied empirically.
•“cognitive task performance” may be operationally defined as the number of
errors detected on a proofreading task during a 10 minute period
•There may be several levels of abstraction when studying a variable. (ie stress is a
very abstract variable. When researchers study stress, they might focus on a
number of stressors – noise, crowding, school, etc. a researcher would probably
choose one stressor to study then develop an operational definition of that type of
stressor. They would then carry out research both pertaining to that specific stress