Lecture 3 Flashcards
What are the three charecteristics of a sensitive research measure?
- Valid.
- Reliable.
- Sensitive – discriminating.
When is a scale valid?
A scale is valid if it measures what it is supposed to measure.
What does validity refer to?
Validity also refers to how well a scale predicts other variables:
When a scale predicts other variables what does it cause?
When used this way, the scale is called the predictor measure and the measure predicted is called the criterion.
What is high validity?
- Least effected by irrelevant factors.
- Maximal sensitivity to changes in relevant factor.
- Few inferences.
Two steps to increase purity, directness, validity, and sensitivity:
What are two steps to increase purity, directness and validity?
Be clear in what you want to measure.
What is reliability?
The consistency of measurement.
Consistency can be conceptualized in different ways:
Therefore, there are different types of reliability.
How is reliability usually measured?
Correlation
What are the four scales of measure?
Nominal.
Ordinal.
Interval.
Ratio.
What is a nominal score of measurement?
Scale of measurement in which the scores are classified by name.
What is the ordinal scale of measurement?
Scale of measurement in which scores are classified by rank.
What are the disadvantages for an ordinal scale of measurement?
Lacks information, there may be big differences between scores:
What are interval scales of measurement?
Scale of measurement that provides not only the order between scores, but also the magnitude of the distance between them.
What does ratio scale have?
Scale of measurement that has all of the properties of nominal, ordinal and interval measures, plus a true zero that represents a complete absence of that characteristic.
