They often describe a series of stages through which an individual moves over time. Each stage requires a more complex construction of understanding than the previous stage, and membership within each subsequent stage depends upon the adoption of a new construction of knowing accumulated during a previous stage. In most cases, stages function in a sequence with transitional phases between them that are often difficult to negotiate smoothly, requiring some sort of developmental effort, and in some cases the experiences within these transitional stages can operate as impediments to development (Miller and Winston, 1990). Pascarella and Terenzini (2005