Within the SMA community, models with the ability to simulate SMA behaviors on many different scales, including atomistic, microscopic, mesoscopic, and macroscopic, have been developed throughout the past few decades. The current research was motivated by the desire to understand the abilities and limitations of macroscopic approaches. Such approaches need to be capable of accurately predicting the SMAs constitutive response in the absence of direct knowledge of the microstructural changes that take place in the SMA. To begin examining this problem, simulations using micro-mechanics and continuum formulations were developed. These simulations were supported by ex-situ macroscopic experiments as well as in-situ neutron diffraction experiments. In both cases, self-accommodated and re-oriented specimens were isothermally cycled from a state where the strain in the principle direction was taken to be zero. The utilization of ex-situ and in-situ experimentation allowed both the macroscopic and microscopic evolutions to be observed such that the underlying microscopic changes responsible for the macroscopic observations could be elucidated. Comparison of the macroscopic responses predicted by the models with those observed experimentally showed that while it is generally thought that there is little need for continuum models to be able to account for variant selection processes, there are situations in which it is desirable to have the ability to capture the differences that result from re-orientation of the martensite variants in models as these processes can substantially alter the macroscopic behavior.