Meyers Unit 2
Correlation
A measure of the extent to which two factors vary together, and thus of how well either factor predicts the other.
survey
A technique for ascertaining the self reported attitudes or behaviors of a particular group, usually by questioning a representative, random sample of graph
Hypothesis
A testable prediction, often implied by a theory
experimental group
In an experiment, the group that is exposed to the treatment, that is, to one version of the independent variable
independent variable
The experimental factor that is manipulated; the variable whose effect is being studied.
standard deviation
a computed measure of how much scores vary around the mean score
confounding variable
a factor other than the independent variable that might produce an effect in an experiment
Scatterplot
a graphed cluster of dots, each of which represents the values of two variables
random sample
a sample that fairly represents a population because each member has an equal chance of inclusion
operational definition
a statement of the procedures used to define research variables
correlation coefficient
a statistical index of the relationship between two things (from -1 to +1)
statistical significance
a statistical statement of how likely it is that an obtained result occurred by chance
Population
all the cases in a group being studied, from which samples may be drawn
informed consent
an ethical principle that research participants be told enough to enable them to choose whether they wish to participate
double-blind procedure
an experimental procedure in which both the research participants and the research staff are ignorant (blind) about whether the research participants have received the treatment or a placebo. Commonly used in drug-evaluation studies
case study
an observation technique in which one person is studied in depth in the hope of revealing universal principles
random assignment
assigning participants to experimental and control groups by chance, thus minimizing preexisting differences between those assigned to the different groups
placebo effect
experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition, which the recipient assumes is an active agent
Natural Observation
observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation
Replication
repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding extends to other participants and circumstances
mean
the arithmetic average of a distribution, obtained by adding the scores and then dividing by the number of scores
range
the difference between the highest and lowest scores in a distribution
illusory correlation
the perception of a relationship where none exists
hindsight bias
the tendency to believe, after learning an outcome, that one would have foreseen it
