Measurement Theories – Classical & IRT (Session 4 and 5) Part I

Part 1- Problem for students to solve: 

1) What is my goal:my goal is to get familiar with those theories such as Classical Test Theory (CTT) & Item Response Theory (IRT); Reliability & Validity. To be honest, right now I am still in the process of understanding those reading and theories.

2) The way to solve the problem: that's why I created  a blog and try to write dome notes and what we have learnd from class. try to summarize them, according to weekly reading assignment. I think it is helpful to me.

           

Measurement Theories – Classical & IRT (Session 4 and 5)

            Topics: 

                        Principles of Classical Test Theory                            

-          O = T + E

-          Measurement Error

-           Reliability

-          Validity

                        Principles of Item Response Theory

-          Θ

-          Local independence of items;

-          item response function (IRF)

DeVellis, R.F. (2003). Scale development: Theory and applications (2nd edition). SAGE Publications, Inc.

-Guideline in Scale Development
step 1: determine clearly what it is you want
step 2: generate an item pool
step 3: determine the format for measurement
step 4: have intial intem popl reviewed by experts
step 5: consider inclusion of validation items
step 6: administer items to a development sample
step 7: evalute the items
step 8: optimize scale length