scholarly journals Which Test is More Reliable for The Testing Statistical Significance of Canonical Correlation Coefficients?

2021 ◽  
Author(s):  
Yasin ALTAY ◽  
Soner YİĞİT
Keyword(s):  
Canonical Correlation ◽  
Statistical Significance ◽  
Correlation Coefficients

scholarly journals Comparison of 1-Repetition-Maximum Performance Across 3 Weightlifting Overhead Pressing Exercises and Sport Groups

2020 ◽  
Vol 15 (6) ◽  
pp. 862-867
Author(s):  
Marcos A. Soriano ◽  
Amador García-Ramos ◽  
Antonio Torres-González ◽  
Joaquín Castillo-Palencia ◽  
Pedro J. Marín ◽  
...  
Keyword(s):  
Statistical Significance ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Assessment Method ◽  
Exercise Group ◽  
Mixed Group ◽  
Training Experience ◽  
Strength And Conditioning ◽  
Repetition Maximum ◽  
Main Effect

Objective: To (1) compare the 1-repetition-maximum (1RM) performance between the push press, push jerk, and split jerk and (2) explore these differences between weightlifters, CrossFit athletes, and a mixed group of athletes. Methods: Forty-six resistance-trained males (age 28.8 [6.4] y; height 180.0 [6.0] cm; body mass 84.1 [10.2] kg; weightlifting training experience 3.64 [3.14] y) participated in this study. The 1RM performance of the push press, push jerk, and split jerk was assessed during the same session in a sequential order (ie, combined 1RM assessment method). Thirty-six participants were retested to determine between-sessions reliability of the 1RM values. Results: Intraclass correlation coefficients (ICCs) and associated 95% confidence intervals (CIs) showed a high between-sessions reliability for the push press (ICC = .98; 95% CI, .95–.99), push jerk (ICC = .99; 95% CI, .98–1.00), and split jerk (ICC = .99; 95% CI, .98–1.00). There was a significant main effect of exercise (η2 = .101) and exercise × group interaction (η2 = .012) on 1RM performance (P < .001), whereas the main effect of group did not reach statistical significance (P = .175). Conclusions: This study provides evidence that the weightlifting overhead press derivatives affect 1RM performance. In addition, the interaction of exercise and sport group was caused by the higher differences in 1RM performance between exercises for weightlifters compared with CrossFit and a mixed group of athletes. Therefore, strength and conditioning professionals should be aware that the differences in 1RM performance between weightlifting overhead-press derivatives may be affected by sport group.

scholarly journals Strength and Reaction Time Capabilities of New Zealand Polo Players and Their Association with Polo Playing Handicap

2019 ◽  
Vol 4 (3) ◽  
pp. 48 ◽  
Author(s):  
Regan Standing ◽  
Russ Best
Keyword(s):  
New Zealand ◽  
Reaction Time ◽  
Grip Strength ◽  
Statistical Significance ◽  
Correlation Coefficients ◽  
Hand Grip Strength ◽  
Left Hand ◽  
Hand Grip ◽  
Right Hand ◽  
Physical Attributes

Polo is an equestrian team sport consisting of four players per team, with level of play determined by cumulative player handicap (−2 to +10 goals), with a higher handicap denoting a better player. There is minimal literature investigating Polo players’ physical attributes, hence the understanding of the physical characteristics that may contribute to an improved handicap are unknown. This study sought to identify the relationship between pertinent strength measures (left and right hand grip strength; absolute and relative isometric mid-thigh pull) and reaction time in Polo handicap in 19 New Zealand Polo players, and ascertain whether handicap could be predicted by these measures. Correlation coefficients were expressed using R values, accompanying descriptors and 90% confidence intervals (C.I.). Variance explained was expressed via the R2 statistic, and statistical significance set at p < 0.05. Right hand grip strength, isometric mid-thigh pull values were found to significantly correlate to and explain variance within Polo player handicap (all moderate to large correlations; p < 0.05). Whereas left hand grip strength (R: 0.380; 90% C.I. −0.011 to 0.670) and reaction time (0.020; −0.372 to 0.406) were non-significant, moderate and trivial correlates and predictors of handicap respectively. Practically, these findings highlight the differing roles between rein and mallet hands of Polo players and emphasise the importance of a strong and stable platform when riding and striking the ball. Lack of association with reaction time may be explained in part by higher handicapped Polo players employing a more proactive approach to the game.

scholarly journals Canonical Correlation Analysis of Data on Human-Automation Interaction

1997 ◽  
Vol 41 (1) ◽  
pp. 62-65 ◽  
Author(s):  
Michael G. Shafto ◽  
Asaf Degani ◽  
Alex Kirlik
Keyword(s):  
Correlation Analysis ◽  
Human Factors ◽  
Field Study ◽  
Canonical Correlation Analysis ◽  
Canonical Correlation ◽  
Statistical Significance ◽  
Study Data ◽  
Commercial Aviation ◽  
Wide Range ◽  
Mission Simulation

Canonical correlation analysis is a type of multivariate linear statistical analysis, first described by Hotelling (1935), which is used in a wide range of disciplines to analyze the relationships between multiple independent and multiple dependent variables. We argue that canonical correlation analysis is the method of choice for use with many kinds of datasets encountered in human factors research, including field-study data, part-task and full-mission simulation data, and flight-recorder data. Although canonical correlation analysis is documented in standard textbooks and is available in many statistical computing packages, there are some technical and interpretive problems which prevent its routine use by human factors practitioners. These include problems of computation, interpretation, statistical significance, and treatment of discrete variables. In this paper we discuss these problems and suggest solutions to them. We illustrate the problems and their solutions based on our experience in using canonical correlation in the analysis of a field study of crew-automation interaction in commercial aviation.

MICROBIAL COUNTS OF INDIVIDUAL PRODUCER AND COMMINGLED GRADE A RAW MILK1

1973 ◽  
Vol 36 (3) ◽  
pp. 146-151 ◽  
Author(s):  
H. E. Randolph ◽  
B. K. Chakraborty ◽  
Otto Hampton ◽  
D. L. Bogart
Keyword(s):  
Statistical Significance ◽  
Correlation Coefficients ◽  
Raw Milk ◽  
Microbial Populations ◽  
Plate Count ◽  
Microbial Counts ◽  
Standard Plate Count ◽  
Standard Plate ◽  
Bulk Tank ◽  
Highly Correlated

Microbial populations of Grade A raw milk samples from 105 individual producers and 74 bulk tank trucks (commingled) were enumerated by Standard Plate Count (SPC), psychrotrophic count (PBC), coliform count (CC), laboratory pasteurized count (LPC), thermophilic count (TBC), yeast and mold count (Y&M), and special penicillin (PEN) and crystal violet tetrazolium (CVT) agar count procedures. In addition, microbial populations were determined by the SPC, PBC, PEN, and CVT procedures after preliminary incubation (PI) of samples. Initial mean counts obtained on individual producer samples were generally lower than those for commingled samples. However, producer samples had higher mean counts after PI. Growth ratios were lower for commingled than for individual producer samples indicating slower growth during PI. Results obtained by the PBC, PEN, and CVT procedures were similar when viewed as correlation coefficients, distribution of samples according to microbial counts, mean counts, and growth ratios during PI. Before PI, the correlation between these three tests was poor and lacked statistical significance when the PBC was &lt;50,000/ml. After PI, the tests were highly correlated (P&lt;0.01) and the r values ranged from 0.8 to 0.9 for samples with PBC levels above 108/ml.

scholarly journals Reproducibility and reliability of three-dimensional soft tissue landmark identification using three-dimensional stereophotogrammetry

2016 ◽  
Vol 86 (6) ◽  
pp. 1004-1009 ◽  
Author(s):  
Asli Baysal ◽  
Ahmet Oguz Sahan ◽  
Mehmet Ali Ozturk ◽  
Tancan Uysal
Keyword(s):  
Soft Tissue ◽  
Statistical Significance ◽  
Intraclass Correlation ◽  
Three Dimensional ◽  
Correlation Coefficients ◽  
Intraclass Correlation Coefficients ◽  
Paired Samples ◽  
Landmark Identification ◽  
The Difference ◽  
Intraexaminer Reliability

ABSTRACT Objective: To evaluate the intraexaminer repeatability and interexaminer reproducibility of soft tissue landmarks on three-dimensional (3-D) stereophogrammetric images. Materials and Methods: Thirty-four stereophotogrammetric images were taken and 19 soft tissue points were identified. The images were obtained using the 3-DMD Face (3-DMD TM Ltd, Atlanta, Ga) system. Two examiners marked 34 images manually with a mouse-driven cursor 4 weeks apart. Intraexaminer marking differences were calculated and classified as &lt;0.5 mm, 0.5–1 mm, and &gt;1 mm. Intraclass correlation coefficients were calculated for intraexaminer reliability. A paired-samples t-test was used to evaluate the difference between the examiners. Interexaminer reproducibility was evaluated by kappa analysis. Statistical significance was set at P &lt; .05. Results: Only one landmark (labiale superior) had an intraexaminer marking difference less than 0.5 mm. Existing landmarks had an intraexaminer difference less than 1 mm, but higher than 0.5 mm. The intraclass correlation coefficients (ICCs) indicated good intraexaminer repeatability for both observers. The ICC range for examiners 1 and 2 was 0.986–1.000 and 0.990–1.000, respectively. Kappa scores showed good interexaminer agreement, especially on the z-axis. Conclusions: Except labiale superior, the soft tissue landmarks used in this study were shown to have moderate reproducibility, but the difference between the landmarks was less than 1 mm, and they had clinically acceptable reproducibility.

scholarly journals Evidence-based practice in primary healthcare from the managerial point of view – a national survey

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Tobias Abelsson ◽  
Helena Morténius ◽  
Ann-Kristin Karlsson ◽  
Stefan Bergman ◽  
Amir Baigi
Keyword(s):  
National Survey ◽  
Primary Healthcare ◽  
Evidence Based Practice ◽  
Statistical Significance ◽  
Correlation Coefficients ◽  
Daily Practice ◽  
Direct Result ◽  
Evidence Based ◽  
Chi Square ◽  
Significance Level

Abstract Background The vast availability of and demand for evidence in modern primary healthcare force clinical decisions to be made based on condensed evidence in the form of policies and guidelines. Primary healthcare managers play a key role in implementing these governing documents. Thus, the aim of this article is to investigate the use and availability of evidence-based practice resources from the perspective of first-line primary healthcare managers. Methods The study is based on a national survey of primary healthcare managers, consisting of 186 respondents, recruited nationally from Sweden. The data was analysed using empirically constructed concepts and validated using factor analysis. A chi-square test was utilized to determine the statistical significance of comparisons. Associations between variables were calculated using Spearman’s correlation coefficients. All tests were two-sided, and the significance level was set to 0.05. Results A majority (97 %) of managers stated that guidelines and policy documents impacted primary healthcare; 84 % of managers observed a direct effect on daily practices. Most of the managers (70 %) stated that some adaptation was needed when new evidence was introduced. The managers emphasized the importance of keeping themselves updated and open to new information about work routines (96 %). Conclusions The study illustrates a nearly unanimous response about the influence of clinical evidence on daily practice. The emphasis on the importance of all staff members keeping their professional knowledge up to date is viewed as a direct result of this effect on daily practice. An information-dense organization such as a primary healthcare organization would have much to gain from increased cooperation with regional information resources such as clinical libraries.

scholarly journals SCALE AND LONG-TERM DYNAMICS OF OKA RIVER BASIN POLLUTION

2021 ◽  
Vol 26 (2) ◽  
pp. 40-53
Author(s):  
R. G. Dzhamalov ◽  
◽  
K. G. Vlasov ◽  
V. Y. Grigorev ◽  
K. G. Galagur ◽  
...  
Keyword(s):  
Water Quality ◽  
River Basin ◽  
Linear Trend ◽  
Statistical Significance ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Kendall Test ◽  
Anthropogenic Load ◽  
Treated Wastewater

Introduction. This article addresses the long-term dynamics of Oka River basin pollution. The basin serves as the main source of drinking water and a receiver of wastewater from a number of regions in European Russia. Methods. We assessed the water quality by 12 main hydrochemical indicators and constructed maps of their distribution with a breakdown into two periods (1990–1999 and 2000–2017). The anthropogenic load along the section in the city of Gorbatov was determined. Spearman’s rank correlation coefficients and their statistical significance were calculated. Results. For 18 gauging stations with 25 and more years of observations, the magnitude of the linear trend (%/year) was estimated using the Theil–Sen estimator, and the statistical significance of the linear trend (Mann–Kendall test) was assessed for individual stations and the entire basin, using a modified Walker test. The runoff of pollutants from the urban territory was estimated between the sections upstream and downstream the cities in the upper reaches of the Oka River basin. The volumes of pollutants in the Oka River from the cities of Orel, Belev and Kaluga were determined for the period of 1990–2017. The calculations of the pollutant runoff, performed between the sections upstream and downstream the cities, made it possible to determine the role of the cities in the formation of point pollution in the upper reaches of the Oka River. The anthropogenic load along the length of the river in terms of the influx of chemicals varies from “low” to “high”. The load is largely due to the intake of pollutants since water bodies and watercourses serve as receivers of both treated and insufficiently treated wastewater from various enterprises. Conclusion. Almost throughout the basin, the water quality is under stress. The statistical analysis showed the existing relationship between a certain type of land use and the concentration of substances in surface waters. It was revealed that the self-cleaning capacity of the river is sufficient to prevent pollutants from accumulating along it.

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