Module 3 Flashcards
Measurement
Collecting observations for research effort
Instrument
- Generic term that researchers use for a measurement device (survey, test, questionnaire, physiologic device).
- Also referred to as a “tool”.
Types of Measures include
- Cognitive (assess knowledge or achievement)
- Affect (interest, values, attitudes)
- Psychomotor (skills)
- Physiologic (indicators of physiologic function such as BP, temp, respirations, ECG/EEG, blood tests, weight, height, etc.)
Reliability
Degree to which measures yield consistent results
Validity
Ability of a scale to measure what was intended to measure.
Reliability is concerned with
The consistency of a measurement method.
A scale that does not produce similar scores for a subject with repeat testing is considered
Unreliable and results in increased measurement error.
Validity determines
How well the instrument reflects the abstract concept being examined.
No instrument is
Completely valid, so researches determine the degree of validity rather than whether validity exists.
Validity will vary from one sample to another and one situation to another: therefore,
Validity testing evaluates the use of an instrument for a specific group or purpose, rather than the instrument itself.
Content validity
Examines the extent to which a measurement method includes all the major elements relevant to the concept being measured.
Convergence validity
Two scales measure the same concept are administered to a group at the same time, and the subjects’ scores on the scales should be positively correlated.
Divergence validity
Two scales that measure opposite concepts, such as hope and hopelessness, are administered to subjects at the same time and should result in negatively correlated scores on the scale.
