PSYC209 Lecture Notes - Lecture 18: Grip Strength, Test Statistic, Statistical Hypothesis Testing

• School: University of Delaware
• Department: Psychology
• Course: PSYC209
• Professor: Ly Agnes

Document Summary

What is the point of hypothesis testing: are changes in some kind of outcome due to chance variability, chance variability : 1. Determine the strength and relationship between two variables how two variables change or don"t change in relation to each other. Measure linear relationships: what is the pearson r statistic, what does the sign and value tell us, pearson dealign w variables measured on interval or ratio scale. 2. relationships between two variables measured on the interval or ratio scale: what are the limitations to interpreting the pearson r, causality, outliers, restriction of range. H1: rho not equal 0 rho= population parameter version of r. H1: not = 0 if r is particular value, there is strength and direction of relationship. Step 3: compute test statistic r= ssxy/ sqrt ssxssy. Ssxssy = sqrt of the two variables independently: direction, the sign on the correlation indicates direction, strength. 3. r can be from -1, 0, +1 r=0. 33 v scattered.