In this article, we attempt to distinguish between the properties of moderator and mediator variables at a number of levels. First, we seek to make theorists and researchers aware of the importance of not using the terms moderator and mediator interchangeably by carefully elaborating, both conceptually and strategically, the many ways in which moderators and mediators differ. We then go beyond this largely pedagogical function and delineate the conceptual and strategic implications of making use of such distinctions with regard to a wide range of phenomena, including control and stress, attitudes, and personality traits. We also provide a specific compendium of analytic procedures appropriate for making the most effective use of the moderator and mediator distinction, both separately and in terms of a broader causal system that includes both moderators and mediators. The purpose of this analysis is to distinguish between the properties of moderator and mediator variables in such a way as to clarify the different ways in which conceptual variables may account for differences in peoples ' behavior. Specifically, we differentiate between two often-confused functions of third variables: (a) the moderator function of third variables, which

Abstract: The case for combining research methods generally, and more specifically that for combining qualitative and quantitative methods, is strong. Yet, research designs that extensively integrate both fieldwork (e.g. case studies) and survey research are rare. Moreover, some journals tend tacitly to specialize by methodology thereby encouraging purity of method. The multi-method model of research while not new, has not been appreciated. In this respect it is useful to articulate and describe its usage through example. By reference to a recently completed study of IS consultant engagement success factors this paper presents an analysis of the benefits of integrating case study and survey research methods. The emphasis is on the qualitative case study method and how it can compliment more quantitative survey research. Benefits are demonstrated through specific examples from the reference study.

The applicability of 5 conventional guidelines for construct measurement is critically examined: (a) Construct indicators should be internally consistent for valid measures, (b) there are optimal magnitudes of correlations between items, (c) the validity of measures depends on the adequacy with which a specified domain is sampled, (d) within-construct correlations must be greater than between-construct correlations, and (e) linear composites of indicators can replace latent variables. A structural equation perspective is used, showing that without an explicit measurement model relating indicators to latent variables and measurement errors, none of these conventional beliefs hold without qualifications. Moreover, a “causal ” indicator model is presented that sometimes better corresponds to the relation of indicators to a construct than does the classical test theory “effect ” indicator model. Factor analysis (Spearman, 1904) and classical test theory (Lord & Novick, 1968; Spearman, 1910) have influenced perspectives on measurement not only in psychology but in most of the social sciences. These traditions have given rise to criteria to select “good ” measures and to a number of beliefs about the

Theories in “soft” areas of psychology lack the cumulative character of scientific knowledge. They tend neither to be refuted nor corroborated, but instead merely fade away as people lose interest. Even though intrinsic subject matter difficulties (20 listed) contribute to this, the excessive reliance on significance testing is partly responsible, being a poor way of doing science. Karl Popper’s approach, with modifications, would be prophylactic. Since the null hypothesis is quasi-always false, tables summarizing research in terms of patterns of “significant differences” are little more than complex, causally uninterpretable outcomes of statistical power functions. Multiple paths to estimating numerical point values (“consistency tests”) are better, even if approximate with rough tolerances; and lacking this, ranges, orderings, second-order differences, curve peaks and valleys, and function forms should be used. Such methods are usual in developed sciences that seldom report statistical significance. Consistency tests of a conjectural taxometric model yielded 94 % success with zero false negatives.

What explains differences in firms' abilities to acquire competitive capabilities? In this paper we propose that embeddedness, in terms of firms' network of bridging ties and linkages to regional institutions, are important sources of variation in firms' acquisition of competitive capabilities. We argue that firm networks rich in bridging ties and firms' participation in regional institutions are critical vehicles for accessing new information, ideas, and opportunities leading to the acquisition of competitive capabilities in geographical clusters. Hypotheses are tested on a stratified random sample of 227 job shop manufacturers located in several regions of the US Midwest using data gathered from a mailed questionnaire. Results from structural equation modeling broadly support the embeddedness hypotheses and suggest a number of novel insights about the link between firms' networks and competitive capabilities.

The SPICE project aims to deliver an international standard for software process assessment by the end of 1996. As part of this project there is an empirical trials phase whose purpose is to ascertain the effectiveness of the prospective SPICE standard. Two of the objectives of the trials phase are: (a) to determine the extent to which SPICEconformant assessments are repeatable (i.e., reliability), and (b) to determine the extent to which SPICE-conformant assessments are really measuring best software process practices (i.e., validity). This paper introduces the theoretical foundations for evaluating the reliability and validity of measurement, suggests some empirical research methods for investigating them in SPICE, and discusses the constraints and limitations of these methods within the context of the SPICE project.

This paper studies redeployment of resources between target and acquiring businesses following horizontal acquisitions. The analysis draws from perspectives that emphasize the strategic importance of resources that are subject to market failure. We define a five-part typology of R&D, manufacturing, marketing, managerial, and financial resources. We show that targets and acquirers frequently redeploy resources following horizontal acquisitions, especially resources that frequently face market failure. We then show that the magnitude of redeployment of each type of resource increases with the asymmetry of the merging businesses ’ relative strength on the resource dimension. The research stresses evolutionary perspectives on business organizations that emphasize the importance of organizational differences in competitive markets. The central premise of our research is that the market for businesses is often more robust than the market for resources. © 1998 John Wiley & Sons, Ltd. Strat. Mgmt. J. Vol. 19, 631–661 (1998)

Abstract—Measurement of software security is a long standing challenge to the research community. At the same time, practical security metrics and measurements are essential for secure software development. Hence the need for metrics is more pressing now due to a growing demand for secure software. In this paper, we propose to use a software system’s attack surface measurement as an indicator of the system’s security. We formalize the notion of a system’s attack surface and introduce an attack surface metric to measure the attack surface in a systematic manner. Our measurement method is agnostic to a software system’s implementation language and is applicable to systems of all sizes; we demonstrate our method by measuring the attack surfaces of small desktop applications and large enterprise systems implemented in C and Java. We conducted three exploratory empirical studies to validate our method. Software developers can mitigate their software’s security risk by measuring and reducing their software’s attack surfaces. Our attack surface reduction approach complements software industry’s traditional code quality improvement approach for security risk mitigation and is useful in multiple phases of the software development lifecycle. Our collaboration with SAP demonstrates the use of our metric in the software development process.

We study “habituation ” to income and to status using individual panel data on the happiness of 7,812 people living in Germany from 1984 to 2000. Specifically, we estimate a “happiness equation ” defined over several lags of income and status and compare the long run effects. We can (cannot) reject the hypothesis of no adaptation to income (status) during the four years following an income (status) change. In the short-run (current year) a one standard deviation increase in status and 52 % of one standard deviation in income are associated with similar increases in happiness. In the long-run (five year average) a one standard deviation increase in status has a similar effect to an increase of 285 % of a standard deviation in income. We also present different estimates of habituation across sub-groups. For example, we find that those on the right (left) of the political spectrum adapt to status (income) but not to income (status).

In the last two decades the interest in the psychosocial development of young children has increased considerably. Not only have new theories and fields of research on the social and emotional development emerged (e.g., attachment theory and research; theories of self-regulation), also behavioral and emotional problems specific to this age range have received more attention than before (e.g., Campbell, 1990, 1995; Richman & Lansdown, 1988; Trad, 1989). However, in the study of psychopathology in very young children, basic issues of assessment, taxonomy, and epidemiology of deviant behavior and development have only been scantily addressed. While for older age groups