NSG 3301 Lecture Notes - Lecture 14: Concurrent Validity, Imrad, Nonprobability Sampling
Document Summary
You must have a rule in order to measure something: such as a ruler, a weight etc. Removes guesswork: - meaning you don"t have to guess how much something weighs or the length of it if you have the proper tools to measure. Less vague than words:- measurement is a language of communication. For example: if you said someone"s temperature was somewhat high, this terminology is different in everyone"s head; something that"s high for someone can be low for someone else. Where as if you said the temperature was 36. 7 degrees there is nothing to question. Obtained score- example: a person"s actual heart rate. True score example: what the person"s heart rate would be if the instrument used to measure was perfect. ( of course no measurement is flawless therefore the true score is hypothetical). Error the difference between the true score and the obtained score. Situational contaminants: measurements can be affected by their surroundings.