2.3 Explanation: Why Do People Do What They Do? Flashcards
What are Variables?
A statistic that describes the average difference between the measurements in a frequency distribution and the mean of that distribution.
What does “Correlation” mean?
Two variables are said to “be correlated” when variations in the value of one variable are synchronized with variations in the value of the other.
What’s the “Correlation Coefficient?”
A mathematical measure of both the direction and strength of a correlation, which is symbolized by the letter “r”.
If “r” = 1, what kind of correlation is it?
Perfect positive correlation
If “r” = -2.3897, what kind of correlation is it?
Negative correlation
If “r” = -1, what kind of correlation is it?
Perfect negative correlation
What’s a Natural Correlation?
A correlation observed in the world around us.
What’s a “Third-Variable Correlation”?
Two variables are correlated only because each is causally related to a third variable
A technique whereby the participants in two groups are identical in terms of a third variable.
Matched Samples Technique
A technique whereby each participant is identical to one other participant in terms of a third variable
Matched Pairs Technique
What’s the “Third-Variable Problem”?
The fact that a causal relationship between two variables cannot be inferred from the naturally occurring correlation between them because of the ever-present possibility of third-variable correlation
What’s the solution to a Third-Variable Problem?
An Experiment!
What are the two key features of Experimentation that help eliminate all the differences between groups?
Manipulation
Random Assignment
What is “Manipulation”?
Changing a variable in order to determine its causal power.
What’s a positive correlation?
Both variables increase or decrease together
What’s a negative correlation?
As one variable increases, the other decreases, or vice versa.
What is “Self-selection”?
A problem that occurs when anything about a participant determines whether he or she will be included in the experimental or control group.
What is “Random Assignment”?
A procedure that lets chance assign participants to the experimental or the control group.
What are Inferential Statistics?
They tell scientists what kinds of conclusions or inferences they can draw from observed differences between the experimental and control groups
What is “Internal Validity”?
An attribute of an experiment that allows it to establish causal relationships.
What is External Validity?
An attribute of an experiment in which variables have been defined in a normal, typical, or realistic way.
What is a “Case Method”?
A procedure for gathering scientific information by studying a single individual.
How does Random Sampling work?
A technique for choosing participants that ensures that everyone in the population has an equal chance of being included in the sample.
What’s a Direct Replication?
An experiment that uses the same procedures as a previous experiment but with a new sample.
