PSYC 300 Study Guide - Final Guide: Latin Square, Covariate, Quasi

• School: University of Maryland
• Department: Psychology
• Course: PSYC 300
• Professor: Richard Yi

Document Summary

Review for exam 3: central tendency general magnitude of scores, Spread how variable or different scores are. Mode the most frequent score in a distribution (nominal data) Median the middle score in ordered distribution, better if there are outliers (robust) Mean average, takes into account magnitude, susceptible to outliers. Good for interval and ratio, not good for nominal or ordinal scales. Normal distribution mean = median = mode. Positively skewed mode > median > mean (big on left) Negatively skewed mean < median < mode (big on right: variance (s2) average squared deviation from mean (standard dev before square root) Total variance = systematic variance + error variance. Error variance variability in scores caused by extraneous variables: causes different influences on dv scores, dealing with error variance: Increase effectiveness of iv, use levels that are different (larger) Randomize error variance across groups (random sampling) Account for it with stat. analysis (avg. scores diff. across treatments)