Validity and Reliability I: What’s the Story? EDU 300 | Newberry College Jennifer Morrison Picture: http://commons.wikimedia.org/wiki/File:Honda_Civic_1995.jpg

Validity and Reliability I What is the difference between reliability and validity? Why are they important concepts? How can you make your assessments more reliable? How can you make your inferences from those assessments more valid? By the end of class you should be able to answer these questions.

Say – I am going to tell you a story. Let’s say there is a teacher (click) and a student (click). The teacher decides to teach a unit on birds (click). Maybe the topic is particularly suited to the teacher’s standards. So the teacher – who is very engaging and accomplished – teaches (click). But what the student thinks and learns is something different (click). Why does this happen? Poor communication Teaching style Student life experiences and background knowledge Student learning style Student needs (physiological, affective filter, etc.) What if the teacher gives an assessment? (owl then eagle) If the assessment assesses what the teacher intends it to assess = reliable If the teacher is able to make accurate judgments and decisions = valid

What happens when the teacher gives an assessment at the end of the owl unit (click)? What if the assessment doesn’t actually match the standards and objectives the teacher intended to teach (click)? For example, the assessment might be a textbook chapter test or a common benchmark assessment developed by the district. What if, for the final assessment, the teacher decides to have students create a diorama showing their personal learning (click)? What’s the problem? Reliability = the extent to which an assessment (consistently) measures what it is supposed to measure What does reliability have to do with this story? Validity = the degree to which a teacher can make accurate inferences abut student learning from an assessment What does validity have to do with this story?

Think about the midterm exam that you just took. Does this exam show what you know (or don’t know) in regard to the content and concepts covered so far in EDU 300? Why or why not? Will M be able to make some accurate judgments and/or instructional decisions based on data from this assessment? Why or why not? I asked you two questions when you took the midterm exam. Which one has to do with validity? Which one has to do with reliability? Basically, you said the test was reliable and we can make valid assumptions based on the results. So…let’s do. In Chapter 4 of Gronlund and Waugh, the authors give a number of statistical ways we can check the validity and reliability of an assessment. We are going to use an item analysis to check the reliability of the midterm exam test items then try and make some valid judgments about your learning as a class.

What’s Due?