A note on campbell's distinction between internal and external validity

The concepts of internal and external validity, developed by Norman Campbell, are widely used to structure methodological thinking about social research. This article points to ambiguities in the interpretation of those terms, both as regards the relationships they refer to as well as the sort of object that is held to be capable of internal and external validity. In addition, it is suggested that the distinction between these types of validity is fundamentally misleading because it reflects a failure to distinguish relations between events and relations between variables. It also rests on the false assumption that we can separate the discovery of causal relationships from the question of whether these apply to other cases than the ones studied. In the final section, an alternative conceptualisation of validity is sketched, one that avoids the problems identified

Evaluating qualitative management research: towards a contingent criteriology

The term qualitative management research embraces an array of non-statistical research practices. Here it is argued that this diversity is an outcome of competing philosophical assumptions which produce distinctive research perspectives and legitimate the appropriation of different sets of evaluation criteria. Some confusion can arise when evaluation criteria constituted by particular philosophical conventions are universally applied to this heterogeneous management field. In order to avoid such misappropriation, this paper presents a first step towards a contingent criteriology located in a metatheoretical analysis of three modes of qualitative management research which are compared with the positivist mainstream to elaborate different forms of evaluation. It is argued that once armed with criteria that vary accordingly, evaluation can reflexively focus upon the extent to which any management research consistently embraces the particular methodological principles that are sanctioned by its a priori philosophical commitments

Front-end process modeling in silicon

Front-end processing mostly deals with technologies associated to junction formation in semiconductor devices. Ion implantation and thermal anneal models are key to predict active dopant placement and activation. We review the main models involved in process simulation, including ion implantation, evolution of point and extended defects, amorphization and regrowth mechanisms, and dopant-defect interactions. Hierarchical simulation schemes, going from fundamental calculations to simplified models, are emphasized in this Colloquium. Although continuum modeling is the mainstream in the semiconductor industry, atomistic techniques are starting to play an important role in process simulation for devices with nanometer size features. We illustrate in some examples the use of atomistic modeling techniques to gain insight and provide clues for process optimization