PSYC37H3 Lecture 4: Lecture 4.docx
Document Summary
Standard deviation conceptually, it is the degree of dispersion in a group of scores. Preferred measure of variability because of its direct relevance to the normal distribution. Skewness is one measure we use to tell us about the symmetry or asymmetry about the distribution. One stretching to the left is lower scores (negative skew) One stretching to the right is higher scores (positive skew) When scores are at low end (positive skew), the test probably contains too few easy items. If scores are massed at the high end (negative skew) the test probably contains too few hard items. People are higher than average in reporting agreeableness. The most basic level of information provided by a psychological test is the raw score. To be at the first percentile is not a good thing in psychology- it means you are at the very bottom at the score.
