Chapter 3 Flashcards
(24 cards)
Variable
Something that changes or varies, so it needs to have at least two levels or values
Constant
Does not vary, stays the same
Measured variable
Levels that are observed and recorded by the researcher
Height, IQ, gender
Manipulated variable
Researcher controls a variable, usually by assigning participants to different levels of that variable
Conceptual variable
Abstract, theoretical concepts such as “infant temperament” and “anxiety”
Operational variables
In order to test their hypothesis with empirical data
To operationalize is to turn a conceptual definition into a measured or manipulated variable
Claim
An argument someone is trying to make
Frequency claim
One variable
Association claim
Two variables that are related
Casual claim
Two variables, one of which causes the other
Positive association
High scores on one variable are associated with high scores on another variable or low scores on one variable are associated with low scores on another variable
Casual claim
One of the variables is responsible for changing the other
One measured variable and one manipulated variable
The two variables convey
Contains tentative language (could, may, suggest)
Construct validity
the degree to which a test measures what it claims, or purports, to be measuring
How well a conceptual variable is operationalized.
The extent to which the operational variables in a study are a good approximation if the conceptual variables.
External validity
The extent to which the results of a study generalize to some larger population, as well as to other times or situations.
Statistical validity
The extent to which the data support the conclusions. Important to ask about the strength of an association and its statistical significance
Internal validity
In a relationship between one variable (A) and another (B), the extent to which A, rather than some other variable (C), is responsible for B
Type I error
False positive, a study might mistakenly conclude that there is an association between two variables in their sample when there actually is no association in the population.
Type II error
A “miss”
A study might mistakenly conclude from a sample that there is no association between two variables when there actually is an association in the population
Covariance
This simply means that two variables are related. Association claims fulfill the criterion
Temporal precedence
One variable comes before the other variable in time.
Internal validity
Also known as the third-variable criterion
A study would be able to eliminate alternative explanation. In other words, variable A is the only thing that changed.
Independent variable
Manipulated or variable (cause) in an experiment
Dependent variable
Measured variable (effect) in an experiment IQ
Random assignment
A method of assigning participants to levels of the independent such that each group is similar as possible
Flipping a coin or rolling a dice
Increases internal validity by controlling for potential alternative explanations
