Alternative Methods of Solving Biasedness in Chi – Square Contingency Table

Some methods of solving the biasedness in Chi–square Contingency table statistic were considered. Phi Coefficient, Contingency Coefficient and Cramer’s V tools were employed to solve the biasedness in the use of Chi–square test. Our results show that any of Phi coefficient, Contingency coefficient or Cramer’s V can be used to describe the association between two variables if the data matrix is 2 x 2. Contingency Coefficient was recommended as a good statistic when the matrix dimension is the same while the Cramer’s V is most adequate when the data matrix differs.

The Error Performances of Some Residual Optimization Methods

A good statistic is unbiased and efficient. Because the encountered data in practice is a sample data with a certain size, the required statistic is not unbiased statistic, but statistic that has small error. When the encountered data is only a sample data, then that can be done is not error optimization but is residual optimization. This study aims to examine the error performance of three methods of residual optimization, they are by minimizing the maximum of absolute residual (MLAD), by minimizing the sum of absolute residual (LAD), and by minimizing the sum of squared residual (LS). Research results using simulation experiments showed that if the data have uniform distribution, the residual optimization method by minimizing maximum of absolute residual get the smallest error. Meanwhile, residual optimization method by minimizing the sum of squared residual get the smallest error when the data have normal or exponential distribution. This property is true when statistics to be estimated are measure of central tendency, regression coefficients, and the response of regression.

Subjective assessment of mastication as parameter for successful prosthetic therapy

Introduction. Success in functional rehabilitation of the craniomandibular system in patients without teeth, which have total prosthesis, can be assessed using different clinical and functional methods. Subjective assessment, motivation, comfort level and functional efficacy are important elements for adaptation to dental prosthesis as well as base for success in prosthetic therapy. The aim of this study was to evaluate the importance of subjective assessment of the mastication in people with new dental prosthesis as well as to assess the value of that parameter in determining the successful prosthetic therapy. Material and Methods. Study was conducted at the Dental Clinic in Novi Sad. Thirty patients (16 males and 14 females) with average age of 62.5 years who received total prosthesis were included. Analysis was done according to the data from the medical records and conducted survey in the form of questionnaire which was adjusted to our clinical examinations. Results. Results showed that 96.6% of the patients were satisfied with new prosthesis. Subjective assessment of the quality of their mastication before therapy showed that 63.4% consider their mastication as unsatisfied, 26.6% satisfied while 10% of toothless patients thought their mastication was good. Statistic analysis showed there was significant difference in subjective assessment before and after the therapy (p<0.01). In fact, there was significant connection between subjective assessment of the mastication and satisfaction with new prosthesis and therapy at all (p<0.01). Conclusion. Patients satisfaction with total prosthesis and subjective assessment of mastication are in direct correlation with successful prosthetic treatment. Results of subjective assessment of the mastication are important and can be used as a parameter for success along with precise survey.

THE HOMOZYGOSITY TEST OF NEUTRALITY

ABSTRACT An earlier paper showed that the homozygosity (of a population or sample) was a good statistic for testing departures from selective neutrality in the direction of heterozygote advantage or disadvantage. It is here shown that homozygosity is also influenced by the presence of deleterious alleles and by other departures from neutrality, but at a lower order of magnitude of effect if the selection coefficients are of the same small order of magnitude. Tables are provided for the significance points and moments of the homozygosity, under the null hypothesis of neutrality.