PSYC 60 Lecture Notes - Lecture 9: Null Hypothesis, Confidence Interval, Statistical Hypothesis Testing
Document Summary
Cohen"s d: original equation included population parameters, estimated cohen"s d is computed using the sample standard deviation. M = 13, = 10, s = 3. Treated mean (m) is one standard deviation above the non-treated mean ( ) Confidence intervals for estimating : alternative technique for describing effect size, estimates treated from the sample mean (m) 99%?: remember, = 1-confidence level (if 90% interval, = . 10, use the t distribution table to find the value of t (example: for df = 9 and = . 10, t = 1. 833) = m 1. 833(sm: solve the rearranged equation, resulting interval is centered around m, are 90% confident that falls within this interval. Factors affecting width of confidence interval: confidence level desired, more confidence desired increases interval width. Psyc 60 ch 9 part 2: less confidence acceptable decreases interval width, sample size, larger sample smaller se smaller interval more exact estimate, smaller sample larger se larger interval less exact estimate.
