Computerized adaptive testing (CAT), while well- grounded in psychometric theory, has had few large- scale applications for high-stakes, secure tests in the past. This is now changing as the cost of computing has declined rapidly. As is always true at such junctures where theory is translated into practice, many practical issues arise that must now be addressed. This paper discusses a number of such issues and sketches out potential problems and potential solutions. Our purpose is to encourage further development of solutions to the issues presented as well as other practical issues facing measurement professionals involved with the implementation of adaptive testing. (30pp.)