Binomial Confidence Intervals and Contingency Tests: Mathematical Fundamentals and the Evaluation of Alternative Methods

Many statistical methods rely on an underlying mathematical model of probability based on a simple approximation, one that is simultaneously well-known and yet frequently misunderstood. The Normal approximation to the Binomial distribution underpins a range of statistical tests and methods, including the calculation of accurate confidence intervals, performing goodness of fit and contingency tests, line- and model-fitting, and computational methods based upon these. A common mistake is in assuming that, since the probable distribution of error about the “true value” in the population is approximately Normally distributed, the same can be said for the error about an observation. This paper is divided into two parts: fundamentals and evaluation. First, we examine the estimation of confidence intervals using three initial approaches: the “Wald” (Normal) interval, the Wilson score interval and the “exact” Clopper-Pearson Binomial interval. Whereas the first two can be calculated directly from formulae, the Binomial interval must be approximated towards by computational search, and is computationally expensive. However this interval provides the most precise significance test, and therefore will form the baseline for our later evaluations. We also consider two further refinements: employing log-likelihood in intervals (also requiring search) and the effect of adding a continuity correction. Second, we evaluate each approach in three test paradigms. These are the single proportion interval or 2 × 1 goodness of fit test, and two variations on the common 2 × 2 contingency test. We evaluate the performance of each approach by a “practitioner strategy”. Since standard advice is to fall back to “exact” Binomial tests in conditions when approximations are expected to fail, we report the proportion of instances where one test obtains a significant result when the equivalent exact test does not, and vice versa, across an exhaustive set of possible values. We demonstrate that optimal methods are based on continuity-corrected versions of the Wilson interval or Yates’ test, and that commonly-held beliefs about weaknesses of tests are misleading. Log-likelihood, often proposed as an improvement on , performs disappointingly. Finally we note that at this level of precision we may distinguish two types of 2 2 test according to whether the independent variable partitions data into independent populations, and we make practical recommendations for their use

From respect to reburial: negotiating pagan interest in prehistoric human remains in Britain, through the Avebury consultation

The recent Avebury Consultation on reburial has drawn considerable public and professional attention to the issue of pagan calls for respect towards the care of human remains. Our work has pointed to the importance of archaeologists and others engaging seriously and respectfully with pagans as significant stakeholders in our heritage. The Avebury Reburial Consultation suggests this dialogue is increasing in strength, but we identify problems in the process. We focus here on approaches to the prehistoric dead and worldviews enabling communication from which calls or ‘claims’ for the reburial of prehistoric pagan human remains, versus their retention for scientific study, are articulated; frameworks for assessing and adjudicating such ‘claims’; and implications for the interest groups concerned. We argue that room must be made for philosophical debate and the emotional and spiritual views of pagans, in order to improve dialogue, develop common ground, and enable participatory decision-making and situational pragmatism

Statistical Properties of Interacting Bose Gases in Quasi-2D Harmonic Traps

The analytical probability distribution of the quasi-2D (and purely 2D) ideal and interacting Bose gas are investigated by using a canonical ensemble approach. Using the analytical probability distribution of the condensate, the statistical properties such as the mean occupation number and particle number fluctuations of the condensate are calculated. Researches show that there is a continuous crossover of the statistical properties from a quasi-2D to a purely 2D ideal or interacting gases. Different from the case of a 3D Bose gas, the interaction between atoms changes in a deep way the nature of the particle number fluctuations.Comment: RevTex, 10pages, 4 figures, E-mail: [email protected]

Interactive Translation vs. Pre-Translation in TMs: A Pilot Study

Translation clients today are looking for high productivity and quality, but are looking for these at reduced costs. Translation Memory (TM) systems are currently among the most popular translation tools on the market and are intended to help translators produce more translations in a short time period while maintaining high quality and consistency in their work. There are two ways of working with a TM system: interactive mode and pre-translation mode. However, there have been no studies to date which attempt to determine whether one mode is superior to the other. This paper describes a pilot study which investigates which of the two produces better results in terms of productivity, quality and translator satisfaction.Les mémoires de traduction (MT) sont présentement l’un des outils de traduction les plus convoités sur le marché. Aujourd’hui, les clients recherchent la productivité et la qualité, sans que cela affecte de façon négative leurs revenus. Deux méthodes s’offrent à l’utilisateur lors de la traduction avec une MT : la traduction interactive et la pré-traduction. Jusqu’à maintenant, on ignore si le choix entre la traduction interactive et la pré-traduction produit un effet sur la productivité, la qualité et la satisfaction du traducteur. Le présent article se propose d’analyser les deux méthodes de traduction avec MT à l’aide d’une méthodologie comparative

De Novo Genome Sequence of "Candidatus Liberibacter solanacearum" from a Single Potato Psyllid in California.

The draft genome sequence of "Candidatus Liberibacter solanacearum" strain RSTM from a potato psyllid (Bactericera cockerelli) in California is reported here. The RSTM strain has a genome size of 1,286,787 bp, a G+C content of 35.1%, 1,211 predicted open reading frames (ORFs), and 43 RNA genes

Augmentative and alternative communication (AAC) training provision for professionals in England

Purpose The purpose of this paper is to document augmentative and alternative communication (AAC) training provision by clinical services in England. Design/methodology/approach A questionnaire was used to obtain the following information concerning AAC training provision; frequency, length, type, content and cost, trainee occupations and numbers, and future training priorities, and information concerning training providers – service type, geographical area. Findings In total, 98 clinical service training providers in England responded. Services commonly reported providing AAC training to speech and language therapists, teaching assistants and teachers. Training around “use of specific AAC products, systems and technology” and “introducing/awareness raising of AAC products” were rated as high priority for future training and were two of the three subject areas where services reported the highest percentage of training. Training was predominantly provided at a foundation (basic) level. Originality/value There is no consensus on the amount or content of AAC training which professionals in England must receive. Evidence suggests that AAC training for pre-qualification professionals is limited and this paper has identified variation in the amount and type of post-qualification AAC training. While knowledge concerning specific AAC systems is necessary, focussing training primarily on this area may not address critical gaps in knowledge. There is a need for specific recommendations regarding AAC training for professionals in this field, to ensure professionals can fully support people who use AAC