How does your model grow? An empirical investigation of the effects of ontological clarity and application domain size on query performance

Semantic data models provide a map of the components of an information system. The characteristics of these models affect their usefulness for various tasks (e.g., information retrieval). The quality of information retrieval has obvious important consequences, both economic and otherwise. Traditionally, data base designers have produced parsimonious logical data models. In spite of their increased size, ontologically clearer conceptual models have been shown to facilitate better performance for both problem solving and information retrieval tasks in experimental settings. The experiments producing evidence of enhanced performance for ontologically clearer models have, however, used application domains of modest size. Data models in organizational settings are likely to be substantially larger than those used in these experiments. This research used an experiment to investigate whether the benefits of improved information retrieval performance associated with ontologically clearer models are robust as the size of the application domains increase. The experiment used an application domain of approximately twice the size as tested in prior experiments. The results indicate that, relative to the users of the parsimonious implementation, end users of the ontologically clearer implementation made significantly more semantic errors, took significantly more time to compose their queries, and were significantly less confident in the accuracy of their queries.

The effects of external linkages on new product innovativeness:an examination of moderating and mediating influences

Our study of 116 new product development projects in Taiwanese Information Technology (IT) firms show that horizontal linkages more strongly impact on new product innovativeness than vertical linkages. The firm's learning ability or absorptive capacity increases new product innovativeness. It also moderates the impacts of corporate and research institute linkages on new product innovativeness. Moreover, we confirm that knowledge gains mediate the positive impacts of absorptive capacity and external linkages on new product innovativeness.

Spatially structured cognitve models of semantic information:the implications for computerised databases

Existing theories of semantic cognition propose models of cognitive processing occurring in a conceptual space, where ‘meaning’ is derived from the spatial relationships between concepts’ mapped locations within the space. Information visualisation is a growing area of research within the field of information retrieval, and methods for presenting database contents visually in the form of spatial data management systems (SDMSs) are being developed. This thesis combined these two areas of research to investigate the benefits associated with employing spatial-semantic mapping (documents represented as objects in two- and three-dimensional virtual environments are proximally mapped dependent on the semantic similarity of their content) as a tool for improving retrieval performance and navigational efficiency when browsing for information within such systems. Positive effects associated with the quality of document mapping were observed; improved retrieval performance and browsing behaviour were witnessed when mapping was optimal. It was also shown using a third dimension for virtual environment (VE) presentation provides sufficient additional information regarding the semantic structure of the environment that performance is increased in comparison to using two-dimensions for mapping. A model that describes the relationship between retrieval performance and browsing behaviour was proposed on the basis of findings. Individual differences were not found to have any observable influence on retrieval performance or browsing behaviour when mapping quality was good. The findings from this work have implications for both cognitive modelling of semantic information, and for designing and testing information visualisation systems. These implications are discussed in the conclusions of this work.

Wealth effects of mergers and acquisitions for US firms: using alternative pricing models

This empirical study employs a different methodology to examine the change in wealth associated with mergers and acquisitions (M&As) for US firms. Specifically, we employ the standard CAPM, the Fama-French three-factor model and the Carhart four-factor models within the OLS and GJR-GARCH estimation methods to test the behaviour of the cumulative abnormal returns (CARs). Whilst the standard CAPM captures the variability of stock returns with the overall market, the Fama-French factors capture the risk factors that are important to investors. Additionally, augmenting the Fama-French three-factor model with the Carhart momentum factor to generate the four-factor captures additional pricing elements that may affect stock returns. Traditionally, estimates of abnormal returns (ARs) in M&As situations rely on the standard OLS estimation method. However, the standard OLS will provide inefficient estimates of the ARs if the data contain ARCH and asymmetric effects. To minimise this problem of estimation efficiency we re-estimated the ARs using GJR-GARCH estimation method. We find that there is variation in the results both as regards the choice models and estimation methods. Besides these variations in the estimated models and the choice of estimation methods, we also tested whether the ARs are affected by the degree of liquidity of the stocks and the size of the firm. We document significant positive post-announcement cumulative ARs (CARs) for target firm shareholders under both the OLS and GJR-GARCH methods across all three methodologies. However, post-event CARs for acquiring firm shareholders were insignificant for both sets of estimation methods under the three methodologies. The GJR-GARCH method seems to generate larger CARs than those of the OLS method. Using both market capitalization and trading volume as a measure of liquidity and the size of the firm, we observed strong return continuations in the medium firms relative to small and large firms for target shareholders. We consistently observed market efficiency in small and large firm. This implies that target firms for small and large firms overreact to new information resulting in a more efficient market. For acquirer firms, our measure of liquidity captures strong return continuations for small firms under the OLS estimates for both CAPM and Fama-French three-factor models, whilst under the GJR-GARCH estimates only for Carhart model. Post-announcement bootstrapping simulated CARs confirmed our earlier results.

Too old to choose? The effects of age and age related constructs on consumer decision making

Ageing of societies is a major challenge to academic research as well as to management. The unstoppable trend of an aging society in most western societies offers opportunities and challenges at the same time. This paper sheds light on the impact of age as well as age-related constructs on relevant consumer attitudes and behavior. More precisely, the empirical study, conducted in the market for cars, examining the relationships between four distinct age constructs and assesses the impact of these age constructs on information gathering, a consumer’s evoked set, and on rand loyalty.

Supervisor-subordinate age dissimilarity and performance ratings:the buffering effects of supervisory relationship practice

Using 394 pairs of employees and their immediate supervisors working in the Information and Communication Technology (ICT) sector in three northern European countries, this study examined the effect of workplace moderators on the link between relational demography and supervisor ratings of performance. Directional age differences between superior and subordinate (i.e., status incongruence caused when the supervisor is older or younger than his/her subordinate) and non-directional age differences were used as predictors of supervisor ratings of occupational expertise. The quality of the supervisor-subordinate relationship and the existence of positive age-related supervisory practices were examined as moderators of this relationship. The results provide no support for a relationship between directional age differences and age-related stereotyping by supervisors in ratings of performance, neither for the effects of age-related supervisory practices. However, high quality supervisor-subordinate relationships did moderate the effects of age dissimilarity on supervisory ratings. The implications of these findings for performance appraisal methodologies and recommendations for further research are discussed.

The interactive effects of mood and trait negative affect in group decision making

Extending the growing interest in affect in work groups, we propose that groups with distributed information make higher quality decisions when they are in a negative rather than a positive mood, but that these effects are moderated by group members' trait negative affect. In support of this hypothesis, an experiment (N = 175 groups) showed that positive mood led to lower quality decisions than did negative or neutral moods when group members were low in trait negative affect, whereas such mood effects were not observed in groups higher in trait negative affect. Mediational analysis based on behavioral observations of group process confirmed that group information elaboration mediated this effect. These results provide an important caveat on the benefits of positive moods in work groups, and suggest that the study of trait × state affect interactions is an important avenue for future research.

The effects of mailing design characteristics on direct mail campaign performance

Designing effective direct mail pieces is considered a key success factor in direct marketing. However, related published empirical research is scarce while design recommendations are manifold and often conflicting. Compared with prior work, our study aims to provide more elaborate and empirically validated findings for the effects of direct mail design characteristics by analyzing 677 direct mail campaigns from non-profit organizations and financial service providers. We investigate the effects of (1) various envelope characteristics and observable cues on opening rates, and (2) characteristics of the envelope content on the keeping rates of direct mail campaigns. We show that visual design elements on the outer envelope – rather than sender-related details – are the predominant drivers of opening rates. Factors such as letter length, provision of sender information in the letter, and personalization positively influence the keeping rate. We also observe that opening and keeping rates are uncorrelated at the campaign level, implying that opening direct mail pieces is only a necessary condition for responding to offers, but not per se a driver of direct mail response.

Some effects of friction and lubrication during hot forging steel.

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Effects of gentamicin therapy on urinary excretion of retinol-binding protein, lysozyme and electrolytes

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The effects of time and location on chemical plant cost

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The toxic effects of enzyme inhibitors on muscle and nerve

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Evidence based assessment of the cardiovascular adverse effects of specific cyclooxy-genase-2 inhibitors

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Some effects of humidity on sexual and asexual reproduction in Phascum Cusphidatum Hedw

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