Introduction

In this chapter, the advantages and basic principles of CALT are briefly introduced first. Then, the four limitations of research on the development of CALT in terms of item pool development are pointed out. Next, it points out that a fundamental issue since the advent of CALT has been what is the construct measured by CALT. After that, CALT validation studies are reviewed, pointing to the limitations of the previous studies. Finally, the research aims and research questions are presented.