Research design multiple-case designs

Yin (Yin, 1994) discusses four criteria forjudging the quality of the research design. After the external validity as already discussed, Yin defines the construct validity, the reliability, and the internal validity. The construct validity is the validity of the operational measures used for the research concepts. In this study construct validity will be addressed by the use of multiple sources for data collection. Case histories,... 

Finally, we were led to the last stage of research where we treated the crystallization from the melt in multiple chain systems [22-24]. In most cases, we considered relatively short chains made of 100 beads they were designed to be mobile and slightly stiff to accelerate crystallization. We could then observe the steady-state growth of chain-folded lamellae, and we discussed the growth rate vs. crystallization temperature. We also examined the molecular trajectories at the growth front. In addition, we also studied the spontaneous formation of fiber structures from an oriented amorphous state [25]. In this chapter of the book, we review our researches, which have been performed over the last seven years. We want to emphasize the potential power of the molecular simulation in the studies of polymer crystallization. 

Processes and functional requirements must be reviewed before issue to the design consultant. The objective of the review, or in some cases multiple reviews, shall be to ensure that processes and functions have been completely and accurately defined, and that performance criteria are unambiguous. Reviews must also determine the consequence of function failure that is, the risk to the research study, manufacturing process, and safety and regulatory compliance. These consequences must be documented so that the delivered solution is appropriate to the business risk, i.e., the design must be relevant to the operating context of the asset. 

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