Chapter 4: Personality
Experimental Research: Independent versus Dependent variables
Advantages: conclusions about cause and effect relationships. Gives
researcher a degree of control
o Demand characteristics (clues in the experimental setting or
procedure that enable the participant to figure out the hypothesis and
act in a manner to support it)
o Low in external validity (the motion that differences in behaviours
that are obtained in the lab may be artificial and not reflect what
happens in real world settings).
o Therefore, low in generalizability (generalizing beyond the lab to
more naturalistic contexts
Independent variable: the variable that is manipulated within an
experiment. Created change and is casual. 2 types. Always has two different
o Manipulated variable: where one level or form of the variable is
applied by the experimenter to a subset of the experiment
participants but a different level or form of the independent variable
is applied to another subset of participants.
o Subject variable: differences between people that can be used to
classify participants into discrete groups when conducting an
Experimental condition: 1 of 2 or more levels of an independent variable
that a participant receives in an experiment.
Random Assignment: a key part of those experiments that are designed to
make inferences about cause and effect relations. Participants should be
allocated randomly to one of the experimental conditions so that additional
variables that might influence behaviour are spread but evenly across the
Between subjects Variable: When one level of an independent variable is
applied to some participants in an experiment but not others.
Within-subject variable: a repeated measure in an experiment. Participant
is exposed to two or more levels of the independent variable. The unique
characteristics of the person are controlled because they are common to all
levels of the independent variable.
Order Effect: when the same person is used repeatedly across different
experimental conditions, the order that the conditions are experienced in
may create a source of bias
Dependent Variable: the outcome variable that is measured in an
experiment. Represents the effect
Interaction or Moderator effect: when the effect of an independent
variable is moderated or influenced by the level of another independent
variable Mediator Effects: a link between two variables which exists as a result of
their mutual link with an intervening variable. This intervening variable
influences both of these variables/ 3 variable.
Additive model: the model that 2 factors make independent contributions to
the prediction of the outcome variable. Also known as main effects model.
Tertial Split: the division of a sample into thirds based on the distribution of
Median split: What a researcher performs when interested in creating only
2 groups. The researcher establishes a midpoint in the range of scored on the
variable in question; people above this midpoint would be in one group and
those below would be in the other.
Regression to the mean: When extreme scores are pulled wither by
decreasing or increasing toward the mean or middle
Measurement Error: What is present when a number that has been
measured and counted is not an accurate reflection of the true value
Correlation research: doesn’t allow us to make assumptions about causality
o Positive correlation: a linear association between variables such that
as one variable tends to increase the other variable tends to increase
to a corresponding degree
o Negative correlation: exists when there is a linear association
between variables such that as one variable decreases the other
variable decreases to a corresponding degree
o Third Variable problem: the problem that a possible influence of a
3 variable limits the ability to conclude that one variable or factor
the cause of another. Both factors could be influenced mutually by
o Directionality issue: the issue that if two variables are related all
that can be stated is that they are associated with each other; it cannot
be assumed that the variability associated with one variable caused or
contributed to the variability of the other variable. Cannot tell which
one came first.
Most studies are self report and correlational studies. Most are cross sectional and
use alone time assessment of a large sample of students.
Structured Assessments: close ended scaled in which the scale content has
already been determined by the people that have constructed the measure.
Respondents select from options provided to them.
Unstructured Assessments: open ended assessments where people
generate their responses. Can be in the form of verbal responses in a
Self-Report Limitations S