KIN 4310 Exam 2 Study Guide Lectures 9 14 Lecture 9 What are the three special types of validity 1 Content Property of a test such that the test items sample the universe of items for which the test is designed 2 Criterion Any variable one wants to predict by measuring another can be concurrent or predictive 3 Construct abstract concept made up of interrelated variables The results of measurement follow from the theory hypothesis The results correlate with other related measures Lecture 10 Define Z score The Z score is the number of standard deviations that a given value x is above or below the mean Review the formulas on Dr Thrasher s presentations How are quartiles partitioned 1 First quartile Q1 2 Second quartile Q2 3 Third quartile Q3 Lecture 11 Define Exploratory Data Analysis EDA EDA is the process of using statistical tools such as graphs measures of center and measures of variation to investigate data sets in order to understand their important characteristics What is an outlier What are its effects An outlier is a value that is located very far away from almost all of the other values It can have a dramatic effect on the mean the standard deviation and the scale of a histogram What is the importance of the probability value p It is used to state how confident we can be about the existence of a particular statistical relationship A value of 1 indicates the event is certain to occur A value of 0 indicates the event is impossible Lecture 12 List the steps of the Scientific Method with respect to inferential statistics 1 Assume that H0 is true 2 Select an appropriate sample 3 Perform experiment or make observations 4 Collect Data 5 Given that H0 is true is it likely that you would end up with the data that you got YES Fail to reject H0 NO Reject H0 The evidence is conclusive Describe Type I and Type II errors 1 Type I error is the mistake of rejecting the null hypothesis when it is true The symbol alpha is used to represent the probability of a type I error 2 Type II error is the mistake of failing to reject the null hypothesis when it is false The symbol beta is used to represent the probability of a type II error Lecture 13 What are the 4 steps of a T test 1 Step 1 Calculate the t value 2 Step 2 After you know the t value you must determine the degrees of freedom df 3 Step 3 Determine the critical value of t 4 Step 4 Compare your t value to the critical value Describe the critical value method Based on a statistical model find a value that partitions 95 of the usual values from 5 of the unusual values Lecture 14 No lecture material In class review