The main purpose of this study is to unravel the impact of the Big Five personality factors on academic performance. We propose a theoretical model with conditional indirect effects of the Big Five personality factors on academic performance through their impact upon academic motivation. To clarify the mixed results of previous studies concerning the impact of neuroticism, we suggest a moderating role of self-efficacy. Hierarchical, moderated mediation and mediated moderation regression analyses were performed on longitudinal data collected from 375 students of a University college in Belgium. The findings revealed a positive indirect effect of neuroticism on academic performance at higher levels of self-efficacy, complemented by a positive direct effect of neuroticism at lower levels of self-efficacy. Finally, this study showed that conscientiousness positively affected academic performance indirectly through academic motivation, but also that it is a condition for the indirect impact of extraversion, neuroticism, and conscientiousness.

This article provides a critical review of scientific, peer reviewed, articles on Facebook between 2006 and 2012. The review shows that while there are yet numerous articles on various aspects of the social network site, there are still many gaps to be filled. Also, due to the limited scope of many articles (in sample sizes as well as in the number of countries included in the studies) and frequent changes to Facebook’s design and features, it is not only necessary to revisit many of these articles but also to integrate their research findings. The review ends with a critical discussion and directions for future research.

Manpower planning is very useful for human resource management in large organizations. Most manpower models are concerned with the prediction of the future behaviour of the staff: they might leave the organization, get promoted or acquire more and new skills. This behaviour can vary a lot among different employees, what makes prediction difficult. It is common to tackle this problem by dividing the whole heterogeneous personnel system in several more homogeneous subgroups. This approach is often used to develop manpower planning models for prediction, control or optimization. Although the division in homogeneous subcategories is a fundamental and important step in the application of the models, up till now literature neglects to discuss a procedure to deal with this in practice. This paper suggests a general framework to find the distinguished homogeneous subcategories by determining and considering observable sources of personnel heterogeneity. obvious actions that could be taken. Several operational research methods are developed to support organizations in their manpower planning challenge. Because of several reasons [3][4][5], almost all academic attention in the past is given to the development of methods for manpower supply forecasting. Those models attempt to predict the future evolution of the current and future employees. Several transitions between states are possible. The two most interesting potential flows of an individual are 'leaving the organization' and 'develop a broader range of skills'. Those transitions influence, respectively, the quantitative and qualitative supply of manpower. This behaviour highly depends on the individual. Several factors cause differences among employees in, for example, motivation, performance or commitment. This personnel heterogeneity makes the manpower supply forecasting difficult. Ugwuowo and McClean [6] made an overview of techniques to handle this heterogeneity. Several manpower planners suggest tackling this problem by dividing the whole heterogeneous personnel system in several more homogeneous subgroups that form a partition of the total personnel system. This simplifies the manpower supply prediction because it becomes acceptable to presume that everyone in the same group evolves analogously. Consequently, the assumption can be made that every employee within a homogeneous group has the same probability to leave the organization or to move towards another homogeneous group. The use of transition probabilities implies that the techniques are only suitable for large organizations. The way that those transitions are estimated and modelled, depends on several different model assumptions. Manpower planners commonly use time-homogeneous Markov models [1, 7], semi-Markov models [8,9], non-time-homogeneous Markov models [10,11] or non-time-homogeneous semi-Markov models [12,13]. The validity of those models highly depends on the homogeneity of the subgroups. In one of the most important reference works on manpower planning [1] the problem of heterogeneity in the sy...

One aspect of Manpower Planning is the investigation of wastage and internal transitions for homogeneous groups of employees in a Manpower system. In the relevant literature, the attainability of a desired stock vector was studied under control by recruitment for time-discrete Markov models. These approaches allow choosing a proper recruitment strategy, resulting in an attainable vector most similar to a desired one. In this paper, this problem will be discussed under stochastic assumptions for attainability after one step. Based on fuzzy set theory, a procedure is introduced that allows evaluating and comparing recruitment strategies, resulting in the determination of a most preferable strategy.

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