# collier last test

 qualitative data categorical or classification dataex. gender, race, where you live, political affiliationmuch test data are qualitativeex. responses to a given test item can be right or wrong or a,b,c, or d quantitative data test scores, reaction time, heart rate, brain-wave measurements lures/distractors wrong answers on a multiple choice test item analysis if a test has only two answers (the right and wrong answer) then indicating which answer was selected is basically the same as indicating whether the correct answer was chosen Two kinds of test theory classical test theory (older)IRT (item response theory) newer replacing classical test theory item discrimination the ability of the item to tell the difference between different peoplean item that everyone got right does not discriminatean item that everyone got wrong does not discriminateitems that are too easy or too difficult have low discriminations item-test/item whole correlation the correltation between a particular item and the scores on the entire test what does it mean when the test-item correlation is high it means that ppl who got the item right tend to have high test scores, and ppl who got it wrong tend to have low test scores.the item discriminates between ppl who knew the material and ppl who didntthe test item correlation is used as an index of item discrimination average test item correlation tells how much they all tend to intercorrelate.can also be called measure of test coherence measure of test coherence whetherthe items all test the same thing average intercorrelation called Cronbach's Alpha and is the most standard measure of test reliability Kuder-Richardson  the version of this formula that applies totests where there are right and wrong answers difficulty the percent correct for an item reliability the item-whole score correlation process of test development 1. make up a bunch of test items and create a test2. give the test to alot of ppl3. get the correlations among the items4. throw out items that correlatepoorly with the reamining items5. if there are too few items left, creae sme new ones and start over6. continue this until the test has enough items tha all have high correlations w/ each other multivariate research gathering many variablestesting and survey research multivariate statistical analysis taking complex data and reducing it to simpler forms qualitative (multivariate methods) categorical or classification dataex. gender, race, poltical affiliation quantitative (mulivariate methods) test scores, reaction time, heart rate, brain-wave measurements factor analysis a method for construct validationgives us a method to Xray inside the vlack box of abstract construct that we are interested in properties of a correlation matrix it contains the correlations or every item with every other itemit is squarethe diagonal elements represent the correlation of each item with itsel, and so these are always 1it is symmetrical simplifying the correlation matrix technique for packaging together variables into super variablesdo this by looking for items that correlate highly with each other, and packaging them togetherif looking at one trait all items should intercorrelate, and should get one super variable that can be name after the trait True/False: Factor analysis and PCA are similar techniques true factors both factor analysis and principal components analysis boil down the correlation matrix to a smaller number of super variables Authorbrittanyball42 ID184017 Card Setcollier last test Descriptioncollier last test Updated2012-11-20T02:17:51Z Show Answers