The MEDLARS regional center at UCLA: a progress report

This paper supplements information given in earlier papers on the UCLA MEDLARS Search Station. Four major machine problem areas in the operation of a decentralized station are identified: adjustments required to run a large information retrieval type program in an academic computing facility serving many users; handicap in running time for COBOL programs; advent of the third generation of computers with attendant preparation; and need for constant current communication among all members of a decentralized network system. Statistics are given for the initial operating period, January-May 1966: 119 search requests received, 109 formulated, and 60 fully processed. Parallel searches with other MEDLARS installations, comparisons of MEDLARS and manual Index Medicus searches, and other search activities are reported.     

Sources of information on medical geography

Adequate research in the peripheral field of medical geography requires familiarity with the literature of medicine, geography, and other environmentally oriented fields. The pertinent literature of the two primary disciplines, as well as that of anthropology, nutrition, and human bioclimatology, is surveyed from a bibliographical point of view. A brief review of historical sources is presented, followed by a discussion of the contemporary organizations, both international and national, active in the field. Emphasis is placed on the publishing programs and projects, maps, atlases, symposia, reports, and other literature sponsored or stimulated by these organizations. Regional bibliographical surveys for East Africa, India, and the Soviet Union are also noted. Pertinent aspects of bibliographies, indexes, abstracts, library card catalogs and accession lists, and other resources are listed, with emphasis on the various subject headings and other approaches to them. Throughout, the sources of information are approached from a multidisciplinary and interdisciplinary viewpoint.     

Time series analysis of knowledge of results effects during motor skill acquisition

Time series analysis was used to investigate the hypothesis that during acquisition of a motor skill, knowledge of results (KR) information is used to generate a stable internal referent about which response errors are randomly distributed. Sixteen subjects completed 50 acquisition trials of each of three movements whose spatial-temporal characteristics differed. Acquisition trials were either blocked, with each movement being presented in series, or randomized, with the presentation of movements occurring in random order. Analysis of movement time data indicated the contextual interference effect reported in previous studies was replicated in the present experiment. Time series analysis of the acquisition trial data revealed the majority of individual subject response patterns during blocked trials were best described by a model with a temporarily stationary, internal reference of the criterion and systematic, trial-to-trial variation of response errors. During random trial conditions, response patterns were usually best described by a "White-noise" model. This model predicts a permanently stationary, internal reference associated with randomly distributed response errors that are unaffected by KR information. These results are not consistent with previous work using time series analysis to describe motor behavior (Spray & Newell, 1986).     

Journals indexed by the AHA Resource Center for Hospital Literature Index and HEALTH database

The American Hospital Association (AHA) Resource Center indexes journals for the Health Planning and Administration (HEALTH) database and Hospital Literature Index (HLI). These journals, designated special list health journals, are selected to provide access to a wide and balanced coverage of hospital and health care administration and health policy literature. This article provides background information on HEALTH and HLI and describes special list health journals in detail (including historical information, information sources, and broad subject divisions). It also discusses AHA policies relating to journal and article selection and current subject distribution of special list health journals.     

Knowledge bases in medicine: a review

Efforts to represent knowledge effectively have been central to progress in various aspects of medical informatics. These efforts range from relatively simple "electronic textbooks" to fairly sophisticated knowledge-based systems, which function as well as, or even better than, human experts faced with similar problems. Knowledge bases have been developed in many fields, but the relatively limited domains and structured language of medicine, as well as the importance of information in the provision of good medical care, have made research in medical knowledge representation an area of intense activity. This paper reviews representative knowledge bases and knowledge-based systems in medicine: electronic textbooks such as PDQ and the Hepatitis Knowledge Base (HKB), rule-based systems such as MYCIN, causal models (e.g., CASNET), and hypothesis- or frame-based systems, exemplified by PIP and INTERNIST-1. The paper describes the relationships among divergent approaches and provides a sense of current and future trends. It examines problems in knowledge-based systems, particularly in knowledge representation and acquisition, and the responses to these challenges. The latter include the use of domain-independent software shells for constructing knowledge bases, the adaptation and use of previously existing knowledge bases, and multiple uses of the same knowledge base for different purposes.