KIN 4310 1nd Edition Lecture 15 Outline of Last Lecture I Example II Excel Normal Distribution III The t test IV The t test Steps V Example Reaction Time Study VI The t test VII The t test Information VIII Question IX Fish Oil Study X The t test Excel Functions Outline of Current Lecture I Review Questions Current Lecture I Review Questions a What is validity i It is the application of a test result is appropriate meaningful and useful b Define 3 kinds of validity These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute i Criterion Validity is when you measure one thing to relate to another thing An example is skin fold calipers the GRE accurately predicts whether a student will successful in grad school ii Content Validity is the extent to which the tool covers the universal item it is intended to construct An example is the texas bar exam covers all the key knowledge that an attorney must have c d e f g h i j k l m n o iii An example of Construct Validity is the depression inventory is a good test for diagnosing clinical depression What is a z score i A z score is a standard score that relates the position of part of a measurement within a sample Describe the normal distribution i Symmetrical around zero possess all real values and the total area is 1 or 100 What is probability i How likely an event is to occur How is probability defined for completely random events i It is defined by an equation of desired results of all results What is a null hypothesis i The negation of what you claim What is a research hypothesis i An assertion what you think is true Which hypothesis do we always assume to be true at the beginning of a study i The null hypothesis Why i If we assume every research hypothesis is true our heads would be conflicted with beliefs What is a one sided hypothesis test A two sided hypothesis test i A one sided hypothesis test has a rejection zone on the right side or on the left side A two sided hypothesis test has 2 rejection zones on each end What is a test statistic i The number that has to do with the hypothesis test itself What is a critical value i A value of the test statistic that is used to determine the result of the hypothesis test How is critical value determined i From the tables in the back of the book What is level of significance p q r s t u v w x i Level of significance is alpha 0 05 and it is the maximum probability that we will use to apply the rare event rule What is a type 1 error i A false positive What is a type 2 error i A false negative What is a p value i The probability of getting a test statistic by chance or the test statistic is more extreme given that the null is true What is a one sample z test i Comparing a sample to a population What information do you need about the population before you can perform a one sample z test i Population mean and the population standard deviation How do you determine critical values of z i By looking at table B1 What is a t test i A hypothesis test where you find the difference between 2 groups Describe the t distribution i Symmetrical around zero has degrees of freedom and has kurtosis What are degrees of freedom i Represent the general size of the data set