PSYC1040 Lecture 9: Lecture 9 - Hypothesis Testing
Document Summary
Different symbols: different one used to describe samples and populations, sample: mean = m, population: mean = weird u, sample: standard deviation = sd, population: standard deviation = o with line. If probability exceeds cut off point, reject null hypothesis - if it doesn"t, retain it. Hypothesising about a single sample score: depression questionnaire, scores can range from 1-50, normal adults, mean = 20, sd = 5. If null hypothesis is true, normal curve with mean = 20 and sd. = 5: step 3: determine cut off, choose level of risk - p = 0. 05 is cut off, find cut off point, where given parameter occurs less than. If null is true, mean = 20, sd = 5. Joe"s z-score = 4. 4 (way off the chart - incredibly rare: step 5: reject or retain null. Joe"s z-score exceeds cut off, reject null and adopt alternative: comes from a population where mean is not equal to 20.
