Standard statistical tests for equality of allele frequencies in males and females and tests for Hardy-Weinberg equilibrium are tightly linked by their assumptions. Tests for equality of allele frequencies assume Hardy-Weinberg equilibrium, whereas the usual chi-square or exact test for Hardy-Weinberg equilibrium assume equality of allele frequencies in the sexes. In this paper, we propose ways...

One of the most common questions about logistic regression is “How do I know if my model fits the data?” There are many approaches to answering this question, but they generally fall into two categories: measures of predictive power (like R-square) and goodness of fit tests (like the Pearson chi-square). This presentation looks first at R-square measures, arguing that the optional R-squares rep...

Methods Canopy fogging was used to sample beetles from 29 trees. The samples were statistically described using Schao and the Simpson diversity index D. Cluster analyses and multi-dimensional scaling (MDS) were performed. The taxonomic and guild structures of the Chilean coleopteran fauna were compared quantitatively with those found in other parts of the world using homogeneity chi-square and ...

Exact distributions of generalized Chi-square and Fisher statistics are used to derive confidence intervals and significance tests for inferring on one or two scaling parameters, respectively, under non-standard assumptions w.r.t. the multivariate sample distribution. The latter may have convex or radially concave density level sets and heavy or light distribution centers and tails. Independent...

A koan is an enigmatic, and often senseless, question posed as an aid to meditation in Zen Buddhism. By “chi-square”, we mean Pearson’s general scheme of a p-value, or tail, statistic that is constructed as a sum of independent random variables, each of which is the square of a normal deviate N(0, 1) (or at least approximately so). Such a statistic is distributed according to the familiar χ2I d...

The "NPD ratio," widely used by yeast geneticists, is of limited applicability and is prone to falsely indicate significant crossover interference in a chi-square test. A simple, better chi-square test for interference in two-factor crosses is described.

BACKGROUND Examining seasonal patterns of birth defects may help to identify environmental risk factors. Because the teratogenic window for most birth defects is during gestational weeks 3 to 8, investigating exposures closer to the timing of conception is important. However, studies are usually based on month of birth, which is not the biologically relevant exposure period and does not account...

Social activities are an important aspect of health and quality of life of the aging population. They are key elements in the prevention of loneliness. In order to create living environments that stimulate older adults to engage in social activities, more insight is needed in the social activity patterns of the aging population. This study therefore analyzes the heterogeneity in older adults' p...

BACKGROUND To examine the seasonality of suicides in Australia and New Zealand during the period 1981 to 1993. METHODS A chi-square test and a harmonic analysis were used to detect the seasonality of the suicide data. RESULTS The reduced amplitude and a smaller proportion of variance accounted for by seasonality suggested the seasonal effect on suicide is greatly diminished. The absence of ...

OBJECTIVE The purpose of the study was to identify technical item flaws in the multiple choice questions submitted for the final exams for the years 2009, 2010 and 2011. METHODS This descriptive analytical study was carried out in Islamic International Medical College (IIMC). The Data was collected from the MCQ's submitted by the faculty for the final exams for the year 2009, 2010 and 2011. T...