Health Sciences 2801A/B Lecture Notes - Lecture 3: Fritter, Standard Deviation, Standard Score

• School: Western University
• Department: Health Sciences
• Course: Health Sciences 2801A/B
• Professor: Christopher Lee

Document Summary

An observed score is a number yielded by a measurement instrument: example: 38 c, or 10/12 on a quiz. A centered score is calculated by subtracting the mean from an observed score: example: 38-37 = 1 c. A standard score is a centered score that has been scaled relative to the standard deviation: a z score is a common form of standard score. A variable is a set of scores that differ to some extent: one score is not a variable (cid:271)ut if you ha(cid:448)e a set a(cid:374)d they"(cid:396)e diffe(cid:396)e(cid:374)t it is a variable. The (cid:862)su(cid:373) of s(cid:395)ua(cid:396)es(cid:863) is a si(cid:373)ple measure of the variability of a set of scores: sum of squares is equal to the sum of the squared centered scores - ss = c2. The (cid:862)(cid:448)a(cid:396)ia(cid:374)(cid:272)e(cid:863) a(cid:374)d (cid:862)sta(cid:374)da(cid:396)d de(cid:448)iatio(cid:374)(cid:863) a(cid:396)e t(cid:449)o othe(cid:396) (cid:449)ays of des(cid:272)(cid:396)i(cid:271)i(cid:374)g the (cid:448)a(cid:396)ia(cid:271)ility of a set of scores.