scholarly journals Erratum: A test of homogeneity of Hardy–Weinberg disequilibrium across strata

2006 ◽  
Vol 14 (12) ◽  
pp. 1321-1321
Author(s):  
Xiao-Lin Yin ◽  
Wen-Qing Ma ◽  
Man-Lai Tang ◽  
Jianhua Guo
Keyword(s):  
Test Of Homogeneity

scholarly journals Vibration Exposure and Transmissibility on Dentist’s Anatomy: A Study of Micro Motors and Air-Turbines

2021 ◽  
Vol 18 (8) ◽  
pp. 4084
Author(s):  
Harish Kumar Banga ◽  
Pankaj Goel ◽  
Raman Kumar ◽  
Vikas Kumar ◽  
Parveen Kalra ◽  
...  
Keyword(s):  
Research Work ◽  
High Amplitude ◽  
Vibration Exposure ◽  
Body Parts ◽  
Descriptive Research ◽  
Air Turbine ◽  
Test Of Homogeneity ◽  
Hand Piece ◽  
Vibration Transmissibility ◽  
Levene Test

The use of dental hand pieces endanger dentists to vibration exposure as they are subjected to very high amplitude and vibration frequency. This paper has envisaged a comparative analysis of vibration amplitudes and transmissibility during idling and drilling with micro motor (MM) and air-turbine (AT) hand pieces. The study aims to identify the mean difference in vibration amplitudes during idling, explore different grasp forces while drilling with irrigant injection by the dentist, and various vibration transmission of these hand pieces. The study utilized 22 separate frequency resonances on two new and eight used MMs and two new and eight used ATs of different brands by observing the investigator at 16 different dentist clinics. The study adopted a descriptive research design with non–probability sampling techniques for selecting dentists and hand pieces. Statistical methods like Levene Test of Homogeneity, Welch ANOVA, independent t-test, and Games–Howell test were utilized with SPSS version 22 and MS-Excel. The results reveal that vibration amplitudes and vibration transmissibility when measured at position 2 are higher than in another position 1. Vibrations during idling for used MMs are more than AT hand pieces, and the used MM (MUD) and used AT (AUA) hand pieces differ due to their obsolescence and over-usage. Vibration amplitudes increase every time with the tightening of grasping of the hand piece. Vibration amplitudes for each grasping style of MM hand piece differ from all other grasping styles of AT hand pieces. Routine exposure to consistent vibrations has ill physical, mental, and psychological effects on dentists. The used hand pieces more hazardous as compared to newer ones. The study suggests that these hand pieces must be replaced periodically, sufficient to break between two operations, especially after every hand piece usage. Hence, the present research work can be further extended by creating some control groups among dentists and then studying the vibration amplitude exposure of various dental hand pieces and subsequent transmissibility to their body parts.

F-Test Alternatives to Fisher’s Exact Test and to the Chi-Square Test of Homogeneity in 2 × 2 Tables

1983 ◽  
Vol 8 (1) ◽  
pp. 59-73 ◽  
Author(s):  
John E. Overall ◽  
Robert R. Starbuck
Keyword(s):  
Beta Distribution ◽  
Binary Response ◽  
Binomial Model ◽  
Chi Square ◽  
Exact Probability ◽  
Exact Test ◽  
Mutual Dependence ◽  
Treatment Groups ◽  
Test Of Homogeneity ◽  
Chi Square Test

A binomial model is proposed for testing the significance of differences in binary response probabilities in two independent treatment groups. Without correction for continuity, the binomial statistic is essentially equivalent to Fisher’s exact probability. With correction for continuity, the binomial statistic approaches Pearson’s chi-square. Due to mutual dependence of the binomial and F distributions on the beta distribution, a simple F statistic can be used for computation instead of the binomial.

A test of homogeneity of several variances against tree ordered alternative

2009 ◽  
Vol 79 (22) ◽  
pp. 2315-2320 ◽  
Author(s):  
Parminder Singh ◽  
Amar Nath Gill ◽  
Narendra Kumar
Keyword(s):  
Test Of Homogeneity

On the use of chi-square analyses in studies of resource utilization

1991 ◽  
Vol 21 (1) ◽  
pp. 58-65 ◽  
Author(s):  
Dennis E. Jelinski
Keyword(s):  
Resource Utilization ◽  
Goodness Of Fit ◽  
Small Sample ◽  
Homogeneity Test ◽  
Type I ◽  
Sample Sizes ◽  
Goodness Of Fit Test ◽  
Chi Square ◽  
Test Of Homogeneity ◽  
Small Sample Sizes

Chi-square (χ2) tests are analytic procedures that are often used to test the hypothesis that animals use a particular food item or habitat in proportion to its availability. Unfortunately, several sources of error are common to the use of χ2 analysis in studies of resource utilization. Both the goodness-of-fit and homogeneity tests have been incorrectly used interchangeably when resource availabilities are estimated or known apriori. An empirical comparison of the two methods demonstrates that the χ2 test of homogeneity may generate results contrary to the χ2 goodness-of-fit test. Failure to recognize the conservative nature of the χ2 homogeneity test, when "expected" values are known apriori, may lead to erroneous conclusions owing to the increased possibility of committing a type II error. Conversely, proper use of the goodness-of-fit method is predicated on the availability of accurate maps of resource abundance, or on estimates of resource availability based on very large sample sizes. Where resource availabilities have been estimated from small sample sizes, the use of the χ2 goodness-of-fit test may lead to type I errors beyond the nominal level of α. Both tests require adherence to specific critical assumptions that often have been violated, and accordingly, these assumptions are reviewed here. Alternatives to the Pearson χ2 statistic are also discussed.

scholarly journals On the Use of Structural Equation Models in Experimental Designs

1989 ◽  
Vol 26 (3) ◽  
pp. 271-284 ◽  
Author(s):  
Richard P. Bagozzi ◽  
Youjae Yi
Keyword(s):  
Latent Variables ◽  
Structural Equation ◽  
Structural Equation Models ◽  
Advantages And Disadvantages ◽  
New Methods ◽  
Special Cases ◽  
Test Of Homogeneity ◽  
General Test ◽  
Step Down ◽  
New Procedures

New procedures are developed and illustrated for the analysis of experimental data with particular emphasis on MANOVA and MANCOVA designs. The authors begin with one-way designs, including overall tests of significance, step-down analyses, and the use of latent variables. Next they describe a general test of homogeneity and consider a procedure that is applicable even under conditions of heterogeneity. Two-way designs then are derived as special cases of the more general n-way case. Finally, advantages and disadvantages of the new methods are considered.

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