Module 8 Statistics

Module 8 Statistics Statistical significance - Not likely to have occurred just by random chance; Often used term in scientific studies; Something other than chance is happening. Hypothesis test - Series if steps that allow us to establish statistical significance Null hypothesis - Beginning a claim; Status quo idea; Usually the parameter is equal to specific ways. What allows establishment of sampling distribution? - Null distribution Alternative Hypothesis (H1 or Ha) - Another theory; Research hypothesis ; there is a difference Test Statistic - Numeric measure of distance from sample value to what is expected under the null hypothesis; Calculate from data; Difference in means, a standard; score; etc. Null distribution - Distribution of the test statistic missing the null hypothesis is true; Can be created stimulation or by a theoretical model; Likely if the null hypothesis is true. P-value - Porpotion of the null distrbution that is more extreme than the observed; How likely is our statistic under Ho If the p value is ________ then the statistic is unlikely given the null hypothesis. - small If the p value is too small, we should _________ the null hypothesis - reject Significance level - Cutoff point for the p-value to indicate if it is too small. a or "alpha" - Typically 10% or less; Most common values (0.05 or 0.01) If p-value is less than a or alpha ________ the null hypothesis. - reject Basic steps of statistical significance - 1.Establish null and alternative hypotheses; 2. Find test statistic; 3. Specifiy null distribution and find p-value; 4. Interpret p-value and make conclusion How do you know when it is a test for proportion? - Subjects are asked a yes/no question; Hypothesis is about a specific proportion; Po (P naught) - A specific proportion of interest like (0.20) P is value is found on the ___ table . - Z