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A fresh look is taken at the problem of bias in information-based attribute selection measures, used in the induction of decision trees. The approach uses statistical simulation techniques to demonstrate that the usual measures such as information gain, gain ratio, and a new measure recently proposed by Lopez de Mantaras (1991) are all biased in favour of(More)
Online learning algorithms often have to operate in the presence of concept drift (i.e., the concepts to be learned can change with time). This paper presents a new categorization for concept drift, separating drifts according to different criteria into mutually exclusive and nonheterogeneous categories. Moreover, although ensembles of learning machines(More)
The current study compares the current and lifetime prevalence of affective disorder in women who have adopted and have natural children (n = 110) with women who only have adopted children (n = 176). There was no difference in lifetime prevalence of psychiatric disorder between the two groups and a nonsignificant trend for women who had born children to(More)
Salmonella enterica isolates (n = 182) were examined for mutations in the quinolone resistance-determining region of gyrA, gyrB, parC, and parE. The frequency, location, and type of GyrA substitution varied with the serovar. Mutations were found in parC that encoded Thr57-Ser, Thr66-Ile, and Ser80-Arg substitutions. Mutations in the gyrB quinolone(More)
Recent work by Mingers and by Buntine and Niblett on the performance of various attribute selection measures has addressed the topic of random selection of attributes in the construction of decision trees. This article is concerned with the mechanisms underlying the relative performance of conventional and random attribute selection measures. The three(More)
A database on 2692 dyspeptic patients over the age of 40 was established, consisting of 73 epidemiological and clinical variables. A tree-based machine learning algorithm (PREDICTOR) was applied to this database, in order to attempt to find rules which would classify patients into 2 groups, i.e., those suffering from gastric or oesophageal cancer, and the(More)
A brief overview of the history of the development of decision tree induction algorithms is followed by a review of techniques for dealing with missing attribute values in the operation of these methods. The technique of dynamic path generation is described in the context of tree-based classiication methods. The waste of data which can result from casewise(More)
In this cross-sectional study, the principles of a technology acceptance model were used to identify variables related to the level of Internet usage by older adults. Community-dwelling older adults aged 60–88 years completed a postal questionnaire survey that elicited responses on the use of the Internet. Out of a sample of 592 older adults (236 males and(More)
The objectives of this research were to identify design attributes to develop easy-to-use websites for older adults. Forty-one males and 58 females (age range 58–90) were asked to retrieve information on a health-related topic from the NHS Direct and Medicdirect websites, and were asked to fill in a website evaluation questionnaire. An exploratory factor(More)