The area-independent effects of habitat complexity on biodiversity vary between regions.

Potential explanatory variables often co-vary in studies of species richness. Where topography varies within a survey it is difficult to separate area and habitat-diversity effects. Topographically complex surfaces may contain more species due to increased habitat diversity or as a result of increased area per se. Fractal geometry can be used to adjust species richness estimates to control for increases in area on complex surfaces. Application of fractal techniques to a survey of rocky shores demonstrated an unambiguous area-independent effect of topography on species richness in the Isle of Man. In contrast, variation in species richness in south-west England reflected surface availability alone. Multivariate tests and variation in limpet abundances also demonstrated regional variation in the area-independent effects of topography. Community composition did not vary with increasing surface complexity in south-west England. These results suggest large-scale gradients in the effects of heterogeneity on community processes or demography.

Selection Power and Selection Labor for Information Retrieval

This study examines the relation between selection power and selection labor for information retrieval (IR). It is the first part of the development of a labor theoretic approach to IR. Existing models for evaluation of IR systems are reviewed and the distinction of operational from experimental systems partly dissolved. The often covert, but powerful, influence from technology on practice and theory is rendered explicit. Selection power is understood as the human ability to make informed choices between objects or representations of objects and is adopted as the primary value for IR. Selection power is conceived as a property of human consciousness, which can be assisted or frustrated by system design. The concept of selection power is further elucidated, and its value supported, by an example of the discrimination enabled by index descriptions, the discovery of analogous concepts in partly independent scholarly and wider public discourses, and its embodiment in the design and use of systems. Selection power is regarded as produced by selection labor, with the nature of that labor changing with different historical conditions and concurrent information technologies. Selection labor can itself be decomposed into description and search labor. Selection labor and its decomposition into description and search labor will be treated in a subsequent article, in a further development of a labor theoretic approach to information retrieval.

Performance Management in the UK Public Sector: addressing multiple stakeholder complexity

Purpose The aim of this paper is to explore the issues involved in developing and applying performance management approaches within a large UK public sector department using a multiple stakeholder perspective and an accompanying theoretical framework. Design/methodology/approach An initial short questionnaire was used to determine perceptions about the implementation and effectiveness of the new performance management system across the organisation. In total, 700 questionnaires were distributed. Running concurrently with an ethnographic approach, and informed by the questionnaire responses, was a series of semi-structured interviews and focus groups. Findings Staff at all levels had an understanding of the new system and perceived it as being beneficial. However, there were concerns that the approach was not continuously managed throughout the year and was in danger of becoming an annual event, rather than an ongoing process. Furthermore, the change process seemed to have advanced without corresponding changes to appraisal and reward and recognition systems. Thus, the business objectives were not aligned with motivating factors within the organisation. Research limitations/implications Additional research to test the validity and usefulness of the theoretical model, as discussed in this paper, would be beneficial. Practical implications The strategic integration of the stakeholder performance measures and scorecards was found to be essential to producing an overall stakeholder-driven strategy within the case study organisation. Originality/value This paper discusses in detail the approach adopted and the progress made by one large UK public sector organisation, as it attempts to develop better relationships with all of its stakeholders and hence improve its performance. This paper provides a concerted attempt to link theory with practice.

Description and search labor for information retrieval

Selection power is taken as the fundamental value for information retrieval systems. Selection power is regarded as produced by selection labor, which itself separates historically into description and search labor. As forms of mental labor, description and search labor participate in the conditions for labor and for mental labor. Concepts and distinctions applicable to physical and mental labor are indicated, introducing the necessity of labor for survival, the idea of technology as a human construction, and the possibility of the transfer of human labor to technology. Distinctions specific to mental labor, particular between semantic and syntactic labor, are introduced. Description labor is exemplified by cataloging, classification, and database description, can be more formally understood as the labor involved in the transformation of objects for description into searchable descriptions, and is also understood to include interpretation. The costs of description labor are discussed. Search labor is conceived as the labor expended in searching systems. For both description and search labor, there has been a progressive reduction in direct human labor, with its syntactic aspects transferred to technology, effectively compelled by the high relative costs of direct human labor compared to machine processes.

A labor theoretic approach to information retrieval

This article synthesizes the labor theoretic approach to information retrieval. Selection power is taken as the fundamental value for information retrieval and is regarded as produced by selection labor. Selection power remains relatively constant while selection labor modulates across oral, written, and computational modes. A dynamic, stemming principally from the costs of direct human mental labor and effectively compelling the transfer of aspects of human labor to computational technology, is identified. The decision practices of major information system producers are shown to conform with the motivating forces identified in the dynamic. An enhancement of human capacities, from the increased scope of description processes, is revealed. Decision variation and decision considerations are identified. The value of the labor theoretic approach is considered in relation to pre-existing theories, real world practice, and future possibilities. Finally, the continuing intractability of information retrieval is suggested.