Health Sciences 2801A/B Lecture Notes - Lecture 3: Standard Score, Standard Deviation
23 Oct 2017
School
Department
Course
Professor
Document Summary
Scores: scores, observed score, centered score, standardized scores (z score, t score, Deviation score: variables, sum of squares, variance, standard deviation, normal deviation, skewed distribution, relationship between variables, sum of products, simple correlation. Observed score is a number yielded by a measurement instrument: e. g. Centered score is calculated by subtracting the mean from an observed score: e. g. Is a (cid:862)total(cid:863) therefore, the more scores, the larger the sum of squares will tend to be. Standard deviation (the most interpretable: the square root of a variance. Degrees of freedom is the number of centered scores minus 1. A variance has degrees of freedom of (n-1) because centered score always sum to zero. In theory, standardized scores have the form of a bell-shaped curve, called the normal distribution. A normal distribution is symmetrical, and the mean is equal to the median. However, in a skewed distribution, the mean is not equal to the median.
