The variable that is measured.
A confounding variable.
The variable that is manipulated.
One that bears no relation to the underlying concepts.
An abstract, theoretical definition of a concept.
A definition of a concept in terms of specific, empirical measures.
Decrease sampling error, but increase non-sampling error.
Increase sampling error, but decrease non-sampling error.
Decrease both sampling error and non-sampling error.
What is the relationship between the number of books children read as 3-year-olds and their reading achievement scores in kindergarten?
Should competitive games be banned from elementary schools?
What does it mean to be a child with a disability included in Ms. Amory's pre-kindergarten class?
The frequency of the effect.
The direction of the effect.
That there will be no difference.