[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Mixture Rasch models, which are often used to investigate response strategy difference, differential item functioning, and test speediness, have gained much attention...

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Differential Item Functioning (DIF) is a test bias that describes the phenomena which measures the same performance level differently because they are from different groups. A...