hello class this is dr. Schwahn here and I'm still seeing a little bit of confusion on reliability and validity so I want to show you guys just a few problems from the key math standardized test which has very high validity and very high reliability I want you to notice something here so let's take a look at question 1 this is form a this is form being question 1 says count to 5 on form a question 2 says count to 4 the only difference is the number the structure is the same that's gonna have a high reliability let's look at this one here is a mother hen and her baby chicks use your finger to point to each chick and count out lab the number of baby chicks and all those look a question to you on Form B here is a mother pig and her baby pigs use your finger to point each baby pig and cannot allow the number of a pigs so same structure again differences pigs versus hand in chicks so that's gonna have high reliability as well 3 breathe the number to me mr. Brue looks like I'm form D read the number to make so notice how the structure of each of these questions is the same when you change that structure you could be affecting the reliability a bit so let's look at this one here are there more pencils or more crowns let's see how they did this one are there more buttons or more paperclips once again the structure is the same so if you want to get high reliability which is always best to do that then you want to keep your structure the same the same number of types of questions the same wording on the questions and then when you go from test to test they're gonna be more reliable so start at 4 and count to 10 and let's look at this one here start at 3 and count to 10 so that's reliability validity well each of these questions measures the exact same concept and the structure is the same so that helps with that this is measuring counting this is measuring counting and I know some of you guys were a little concerned about how you do this how you label the problem which when you're doing this informally like we're doing for the assignment you can decide how you want to label it but when you do this more with formal assessments you want to know the exact label you should have it so I hope that clears up a little bit more about validity and reliability because as you look at this you see the structure is the same the numbers change that will get you really high reliability and that's something I want you guys to keep in mind as you're making your assessments and looking at different assessments all right guys thanks a lot and I will talk to you soon