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PurposeThe purpose of this paper is to propose a framework for describing and evaluating the representativeness of a small set of search results extracted from the original results: this is deemed desirable in information retrieval in enterprise information systems.Design/methodology/approachThe paper proposes a combined measure, namely RFβ, to evaluate the extracted small set in terms of the notions of coverage and redundancy. Data experiments were conducted on three different extraction strategies to evaluate the representativeness, i.e. coverage and redundancy.FindingsBoth from intuitive and experimental perspectives, the proposed coverage measure, redundancy measure and RFβ measure could effectively evaluate the representativeness.Research limitations/implicationsThe search results, e.g. in the form of documents and texts, are modeled using a vector space model and cosine similarity. Semantic models and linguistic models could be further introduced into this research to improve the proposed measures.Practical implicationsWith the rapidly growing need for information retrieval in enterprise information systems, the representativeness of search results become more desirable and important for search engine users. The well‐designed representativeness measures will help them achieve satisfactory results.Originality/valueThe originality of the paper lies in the definition of representativeness of a small set of search results extracted from the original results. This focuses on the two aspects of coverage rate and redundancy rate both from intuitive and experimental perspectives.

PurposeTo reveal and analyze the key issues concerning information systems management in Mainland China.Design/methodology/approachBased on data collected from 286 Chinese companies, 12 top key issues in information systems management in Mainland China are ranked and compared with the results of an earlier study, as well as those from western countries.FindingsWhile the top three critical issues remain unchanged, largely due to the centralized decision‐making mechanism, mandatory management style, and less experience of IT/IS applications, there are distinguishable changes that took place in the past few years. Furthermore, there are different results between different sectors of companies, reflecting respective characteristics and historical development processes of the sectors.Research limitations/implicationsExtended data and measures are required for in‐depth investigation in specific individual industries.Practical implicationsThe study could be helpful for understanding the situations and challenges in information systems management in China and planning IT/IS strategies accordingly.Originality/valueThe paper offers practical help for managers to better understand the IT/IS application context in China. Meanwhile, researchers interested in IT/IS management in China can use the information provided by this paper to guide their inquiry.

ABSTRACTConsumer information search (CIS), the process by which a consumer browses and inspects a shopping environment for appropriate information to select a product or service from available options, has been a research focus in the context of online business. One of the key questions related to CIS is how to determine how much information to search (i.e., when to stop searching). Extensive literature on behavioral science has revealed that consumers often search either "too little" or "too much," even with the help of existing consumer decision support systems (CDSSs). To address this issue, this article introduces a new method of CDSSs that provides effective estimation of incremental search benefits. The method, called the personalized distribution‐based prediction method (PDM), is developed from the perspective of machine learning and utilizes consumer preference information generated by collaborative filtering (CF) algorithms. In contrast to related methods that assume that all consumers follow the same distribution function in terms of product preference, the PDM method is designed to consider the diversified search behaviors of consumers through the incorporation of heterogeneous preference distribution functions. Experiments based on data provided by Netflix illustrate that the proposed method is effective and advantageous over existing applicable techniques. Theoretical analyses are also provided to explain the advantageous performance of PDM.

TaiNan Lin,1,* Yan Yang,2,* JinHua Lin,1 JiHui Zhang,1 Qian Wen,1 XiaoLu He,1 GuoQing Chen1 1Department of Ophthalmology, Fujian Provincial Governmental Hospital, Fuzhou, 350003, People's Republic of China; 2Fujian Center for Disease Control and Prevention, Fuzhou, 350001, People's Republic of China*These authors contributed equally to this workCorrespondence: TaiNan LinDepartment of Ophthalmology, Fujian Provincial Governmental Hospital, No. 67 of Gupin Street, Gulou District, Fuzhou, 350003, People's Republic of ChinaTel +86 591 88013047Fax +86 591 88013003Email lintainandr@163.comObjective: This study aimed to compare the macular and choroidal thicknesses and blood-flow parameters of patients with intermediate and simple juvenile moderate myopia in order to provide a greater understanding of the pathogenesis of myopia and a basis for its prevention.Methods: Participants were selected from patients under the age of 18 with moderate myopia who were treated in our ophthalmic clinic between June and December 2019. Seventy-five right eyes were selected from participants with a mean spherical equivalent ranging from − 6.0 to − 3.0 D. These samples were divided into two groups based on eye axial length (AL). The thicknesses of the macula and choroid, the area of the foveal avascular zone (FAZ), and the blood flow density of the macular capillaries were measured, intergroup comparison was conducted.Results: The average area of the FAZ was larger in the intermediate group than in the simple group. PERIM in the upper half was lower in the intermediate group than in the simple group, and the blood-flow density in the lower half of the macular area was higher in the simple group than in the intermediate group. The blood-flow density within 1 mm of the fovea centralis and the downward blood-flow density were higher in the intermediate group than in the simple group. The thicknesses of the lower part of the FAZ, the choroid of the fovea centralis, and the choroid under the retina were all larger in the intermediate group than in the simple group.Conclusion: The area of the FAZ in patients with intermediate juvenile moderate myopia is larger than that in patients with simple myopia; the choroid in the fovea of macula compensatorily increases, and blood flow density also increases; the thickness of the choroid under the retina increases with myopia.Keywords: choroidal blood flow, choroidal thickness, myopic adolescents, moderate myopia, optical coherence tomography angiography