Note on Closure Correlation

1974 ◽  
Vol 11 (11) ◽  
pp. 1616-1619 ◽  
Author(s):  
Erwin Zodrow
Keyword(s):  
Correlation Coefficients ◽  
T Test ◽  
Closure Property ◽  
Great Care ◽  
Caveat Emptor ◽  
Zero Correlation ◽  
Statistical Assumptions ◽  
Closed Data ◽  
T Matrix ◽  
Closure Correlation

Given a matrix of product-moment correlation coefficients computed on 'closed data' (a system of percentage variables), the test of departure from zero correlation is clearly inappropriate because closure of data imposes non-zero correlation.Subroutine CHAYES estimates 'Null Correlations' and calculates a t-matrix which may be used to test the hypothesis that observed product-moment correlations are due to the closure property. The calculated t-matrix is at best an approximation. This is found in certain mathematical assumptions leading to this t-test, and the recognition that statistical assumptions in the theory of t-testing are not satisfied. Great care must be exercized in accepting or rejecting correlations by this test. Therefore, results of the t-test are no substitute for sound geological reasoning, caveat emptor.

scholarly journals PENGARUH PENDIDIKAN/PELATIHAN, SARANA PRASARANA DAN ANGGARAN TERHADAP KINERJA PEGAWAI APARAT PENGAWAS INTERNAL PEMERINTAH (APIP) PADA INSPEKTORAT DAERAH KABUPATEN KAPUAS

KINDAI ◽  
2021 ◽  
Vol 17 (2) ◽  
pp. 242-252
Author(s):  
Suprianto
Keyword(s):  
Employee Performance ◽  
Correlation Coefficients ◽  
Education And Training ◽  
T Test ◽  
Test Reliability ◽  
Analysis Technique ◽  
Training Variable ◽  
Kolmogorov Smirnov ◽  
The Government ◽  
And Training

Abstract : This study aims to determine the magnitude of the influence of Training, Infrastructure and Budget on the Performance of the Government Internal Supervisory Apparatus (APIP) at the Regional Inspectorate of Kapuas Regency . Data was collected using questionnaires and documentation Questionnaires are used to measure the variables of Education and Training, Infrastructure and Budget and employee performance. Data analysis technique used is U ji validity , test reliability , test correlation coefficients , t-test (Partial) , Test Multicollinearity , Kolmogorov-Smirnov test (Test Normality) , ANOVA (F test Simultaneous) and Test Multiple Linear Regression . The results showed that the budget has a positive and significant effect on employee performance . The results of the t test between X 3 (Budget) and Y (APIP Performance) show t count = 3.114. While the t table (α = 0.05 ; db residual = 17) is 1.740. Because t arithmetic > t table is 3.114 > 1.740 or sig t value (0.008) < = 0.05, the effect of X 3 (Budget) on Y (APIP Performance) is significant. This means that Ho is rejected and H1 is accepted, so it can be concluded that APIP's performance can be significantly affected by the Budget .Based on the coefficient because it has the greatest beta coefficient value of 0.707 when compared to the regression coefficient of the education and training variable and infrastructure. this means that H 0 is rejected and h 3 is received, so that it can be concluded that the budget is the dominant variable affecting the performance of internal government regulatory authorities in Kapuas district inspectorate valued at 70.7% and the remaining 29 , 3 % is influenced by other variables not examined in this research. Keywords: Training, Infrastructure and Budget , Employee Performance.   Abstrak : Penelitian ini bertujuan untuk mengetahui besarnya pengaruh Diklat, Sarana Prasarana Dan Anggaran Terhadap Kinerja Pegawai Aparat Pengawas Internal Pemerintah (APIP) pada Inspektorat Daerah Kabupaten Kapuas. Pengumpulan data dilakukan dengan menggunakan koesioner dan dokumentasi. koesioner digunakan untuk mengukur variabel Diklat, Sarana prasarana dan Anggran serta kinerja pegawai. Adapun teknik analisis data yang digunakan adalah Uji Validitas, Uji Reliabilitas, uji Koefisien Korelasi, Uji t (Parsial), Uji Multikolinearitas, Uji Kolmogorov Smirnov (Uji Normalitas), ANOVA (uji F Simultan) dan Uji Regresi Linear Berganda. Hasil Penelitian menunjukkan bahwa Anggran mempunyai pengaruh yang positif dan signifikan terhadap kinerja pegawai. Hasil t test antara X3 (Anggaran) dengan Y (Kinerja APIP) menunjukkan t hitung = 3,114. Sedangkan t tabel (α = 0.05 ; db residual = 17) adalah sebesar 1,740. Karena t hitung > t tabel yaitu 3,114 > 1,740 atau nilai sig t (0,008) < α = 0.05 maka pengaruh X3(Anggaran) terhadap Y (Kinerja APIP) adalah signifikan. Hal ini berarti Ho ditolak dan H1 diterima, sehingga dapat disimpulkan bahwa kinerja APIP dapat dipengaruhi secara signifikan oleh Anggaran. Berdasarkan koefisien dikarenakan mempunyai nilai koefisiensi beta paling besar 0,707 jika Dibandingkan dengan koefisien regresi variabel Diklat dan sarana prasarana. hal ini berarti h0 ditolak dan h3 diterima, sehingga dapat disimpulkan bahwa anggaran merupakan variabel yang dominan mempengaruhi kinerja aparat pengawas internal pemerintah pada inspektorat daerah kabupaten Kapuas senilai 70,7% dan sisanya 29,3% dipengaruhi oleh variabel lain yang tidak diteliti dalam penelitian ini. Kata Kunci: Diklat, Sarana prasarana dan Anggaran, Kinerja Pegawai.  

scholarly journals TANAKA AND JOHNSTON'S MIXED DENTITION VALIDITY: AN ANALYSIS AMONG YEMENI ADULTS IN SANA'A CITY

2022 ◽  
Author(s):  
Waleed Abdualaziz Mohammad Dahag ◽  
Abdulwahab Ismail Mohamed Al-Kholani ◽  
Taghreed Ahmed M Al-Kibsi ◽  
Hussein Shoga Al-Deen ◽  
Hassan Abdulwahab Al-Shamahy ◽  
...  
Keyword(s):  
Peer Review ◽  
School Children ◽  
Correlation Coefficients ◽  
T Test ◽  
Mixed Dentition ◽  
Primary School Children ◽  
Regression Equations ◽  
Chi Square ◽  
Anterior Teeth ◽  
Tooth Width

Introduction and objective: Mixed dentition space analysis methods via Tanaka-Johnston analysis are regularly used all over the world. Conversely, the appropriate of this analysis between different ethnic groups is dubious. The study aimed to test the appropriate of the Tanaka-Johnston analysis for Yemeni adults and to arise regression equations designed for Yemen population if needed.  Methods: The study included two hundred and twenty-seven (106 males and 121 females) Yemenis from Sana'a University, University of Science and Technology, and Al-Rehab Private Clinic. The mesiodistal widths of the four permanent lower canines, incisors, and premolars for the entire quadrants were determined with a digital caliper to the nearest 0.01 mm. To compare average presentation values ​​derived from this study with values ​​derived using Tanaka-Johnston equations, Student's paired t-test was used, as well as the chi-square (χ2) test used for appropriateness of fit. Result: Gender differences were observed in the total mesiodistal width of both canines and premolars in both arches as revealed by the t-test (p < 0.001). The sum of the actual mesiodistal width of the canines and premolars was compared with the expected widths derived from the Tanaka and Johnston equation and significant differences (p<0.001) were found. Regression analysis indicated that the sum of the mesiodistal width of the permanent mandibular incisors is a good predictor of that of un-erupted canines and premolars, with correlation coefficients ranging from 0.51 to 0.61. Accordingly, two linear regression equations were developed to predict tooth width for Yemeni males and females. Conclusion: It was concluded from this study that the Tanaka-Johnston analysis did not accurately predict the mesiodistal width of the unruptured canines and premolars of the Yemeni population. Moreover, new regression equations have been developed for the research sample that can be a standard for Yemen. However, further studies must be performed to verify the applicability and accuracy of these equations.                   Peer Review History: Received: 10 November 2021; Revised: 12 December; Accepted: 29 December, Available online: 15 January 2022 Academic Editor: Dr. Asia Selman Abdullah, Pharmacy institute, University of Basrah, Iraq, [email protected] UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency.  Received file:                Reviewer's Comments: Average Peer review marks at initial stage: 6.5/10 Average Peer review marks at publication stage: 7.5/10 Reviewers: Dr. A.A. Mgbahurike, University of Port Harcourt, Nigeria, [email protected] Rola Jadallah, Arab American University, Palestine, [email protected] Similar Articles: PREVALENCE AND CAUSES OF TRAUMATIC DENTAL INJURIES TO ANTERIOR TEETH AMONG PRIMARY SCHOOL CHILDREN IN SANA'A CITY, YEMEN OCCLUSAL CHARACTERISTICS OF THE PRIMARY DENTITION AMONG A SAMPLE OF YEMENI PRE-SCHOOL CHILDREN

Detecting Nonlinear Associations, Plus Comments on Testing Hypotheses About the Correlation Coefficient

2001 ◽  
Vol 26 (1) ◽  
pp. 73-83 ◽  
Author(s):  
Rand R. Wilcox
Keyword(s):  
T Test ◽  
Test Statistic ◽  
The Social ◽  
Zero Correlation ◽  
Common Strategy ◽  
Kolmogorov Smirnov ◽  
Nonlinear Associations ◽  
Student’S T ◽  
Von Mises ◽  
Student’S T Test

Let (Yi,Xi ), i = 1, . . . , n, be a random sample from some p + 1 variate distribution where Xi is a vector of length p. In the social sciences, the most common strategy for detecting an association between Y and the marginal distributions is to test the hypothesis that the corresponding correlations are zero using a standard Student’s t test. There are two practical problems with this strategy. First, for reasons described in the article, there are situations where the correlation between two random variables is zero, but Student’s t test is not even asymptotically correct. In fact, the probability of rejecting can approach one as the sample size gets large, even though the hypothesis of a zero correlation is true. Of course, one can also apply standard methods based on a linear regression model and the least squares estimator, but the same practical problems arise. Second, Student’s t test can miss nonlinear associations. This latter problem is the main motivation for this article. Results of a former study suggest an approach that avoids both of the difficulties just described. Based on simulations, it is found that the Cramér-von Mises form of the test statistic is generally better than the Kolmogorov-Smirnov form. Situations arise where this method has less power than Student’s t test, but this is due in part to t test’s use of an incorrect estimate of the standard error.

Parabrachial gustatory neural activity during licking by rats

1991 ◽  
Vol 66 (3) ◽  
pp. 974-985 ◽  
Author(s):  
H. Nishijo ◽  
R. Norgren
Keyword(s):  
Citric Acid ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Hierarchical Cluster ◽  
T Test ◽  
Fluid Delivery ◽  
The Mean ◽  
Parabrachial Nuclei ◽  
Hierarchical Cluster Analyses ◽  
Paired T Test

1. A total of 51 single neurons was recorded from the pontine parabrachial nuclei of three rats being given sapid stimuli either via intraoral infusions or during spontaneous licking behavior. In 46 neurons, sapid stimuli elicited significant taste responses; of these, 28 responded best to NaCl, 15 to sucrose, 2 to citric acid, and 1 to quinine HCl. The remaining five neurons responded significantly only to water. The mean spontaneous rate of taste neurons during the intraoral infusion and licking sessions was 11.1 +/- 1.1 and 10.8 +/- 1.2 (SE) spikes/s, respectively. 2. Of the 39 neurons tested during both licking and intraoral infusions, four responded significantly only to water via either route. The remaining 35 neurons responded significantly to at least some sapid stimuli. The best-stimulus categories remained the same regardless of the route of fluid delivery (24 NaCl best, 10 sucrose best, 1 citric acid best). When the rats were licking the stimuli, nine taste neurons responded significantly to only one sapid chemical [6 Na specific (Ns) and 3 sucrose specific (Ss)] but were more broadly tuned during intraoral infusions. Conversely, three taste neurons that responded specifically during intraoral infusions (3 Na specific) were not as specific when the animal licked the same fluids. 3. Thirty-five taste neurons were tested via both stimulus routes. These data were compared in three ways. First, for each neuron, the responses elicited during licking and intraoral infusions were compared for each of the four standard sapid stimuli. The Pearson correlation coefficients for the 35 taste neurons ranged from 0.9997 to 0.6785, with a mean at 0.953 +/- 0.012 (SE). The second comparison was between stimulus routes across chemicals. With the use of raw responses, the correlation coefficients for NaCl, sucrose, citric acid, and QHCl ranged from 0.925 to 0.778 (t test, P less than 0.0001). With the activity elicited by water subtracted (corrected responses), the correlation coefficients for NaCl, sucrose, citric acid, and QHCl were 0.900, 0.795, 0.369, and 0.211, respectively. The coefficient for QHCl was not significant (t test, P greater than 0.05). Finally, the mean responses to NaCl, sucrose, and citric acid delivered by both routes were compared and found not to differ (paired t test, P greater than 0.05). 4. In separate hierarchical cluster analyses for the licking and infusion data, the largest cluster in each contained all of the Na-best neurons and the next largest, all of the sucrose-best cells.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Association between Serum Albumin and Hypothyroidism in Preeclampsia: A Case-control Study

2021 ◽  
Author(s):  
Nineetha Muraleedharan ◽  
M Saboora Beegum
Keyword(s):  
Serum Albumin ◽  
Case Control Study ◽  
Correlation Coefficients ◽  
Case Control ◽  
Thyroid Stimulating Hormone ◽  
T Test ◽  
High Morbidity ◽  
Chi Square ◽  
Increased Risk ◽  
Control Study

Introduction: Preeclampsia is a cause of high morbidity and mortality in pregnant women. Serum albumin is found to be low in preeclampsia. Few recent studies have shown a state of hypothyroidism in preeclampsia. Aim: To find the association between the serum albumin and thyroid hormone levels in preeclampsia and seek to find if hypoalbuminemia increases the risk of hypothyroidism. Materials and Methods: A case-control study was done at Department of Biochemistry and the Department of Obstetrics and Gynaecology of Government Medical College, Thiruvananthapuram, Kerala, with 40 preeclampsia cases and 40 normal pregnant controls, in 30-38 week gestation. Serum albumin and thyroid profile-Total T3, Total T4, Thyroid Stimulating Hormone (TSH), freeT3 (fT3), freeT4 (fT4) were tested. Statistical analysis was done with Student’s t-test, Chi-square, Fischer’s t-test and Pearson’s correlation coefficients. Results: The mean serum albumin was significantly lesser in preeclampsia (3.11±0.39) than in controls (3.7±0.14 g/dL). Thyroid hormones were significantly decreased in preeclampsia. TSH was significantly raised (3.76±1.55 mIU/L) in preeclampsia compared to normal pregnant ladies (2.3±0.94 mIU/L). In cases with hypoalbuminemia, risk for hypothyroidism was 2.85 times compared to those with normal albumin but was not statistically significant. In severe preeclampsia, there was a two times increased risk. There was a negative correlation of TSH and positive correlation for fT4 with serum albumin. However, this was statistically not significant. Conclusion: Hypothyroidism in preeclampsia was not significantly correlated with hypoalbuminemia in this study. Thus hypoalbuminemia did not significantly increase the risk for hypothyroidism in our study. Further studies are needed to determine the risk factors affecting thyroid function in preeclampsia.

scholarly journals Correlation Coefficients: Mean Bias and Confidence Interval Distortions

2011 ◽  
Vol 1 (2) ◽  
pp. 52 ◽  
Author(s):  
Richard L. Gorsuch ◽  
Curtis S. Lehmann
Keyword(s):  
Confidence Interval ◽  
Confidence Intervals ◽  
Correlation Coefficients ◽  
Standard Errors ◽  
Design Issues ◽  
Normal Distributions ◽  
Zero Correlation ◽  
Order Of Magnitude ◽  
Restriction Of Range ◽  
Z Transformation

Non-zero correlation coefficients have non-normal distributions, affecting both means and standard deviations. Previous research suggests that z transformation may effectively correct mean bias for N's less than 30. In this study, simulations with small (20 and 30) and large (50 and 100) N's found that mean bias adjustments for larger N's are seldom needed. However, z transformations improved confidence intervals even for N = 100. The improvement was not in the estimated standard errors so much as in the asymmetrical CI's estimates based upon the z transformation. The resulting observed probabilities were generally accurate to within 1 point in the first non-zero digit. These issues are an order of magnitude less important for accuracy than design issues influencing the accuracy of the results, such as reliability, restriction of range, and N. DOI:10.2458/azu_jmmss_v1i2_gorsuch

scholarly journals Correlation Coefficients: Mean Bias and Confidence Interval Distortions

2011 ◽  
Vol 1 (2) ◽  
pp. 52 ◽  
Author(s):  
Richard L. Gorsuch ◽  
Curtis S. Lehmann
Keyword(s):  
Confidence Interval ◽  
Confidence Intervals ◽  
Correlation Coefficients ◽  
Standard Errors ◽  
Design Issues ◽  
Normal Distributions ◽  
Zero Correlation ◽  
Order Of Magnitude ◽  
Restriction Of Range ◽  
Z Transformation

Non-zero correlation coefficients have non-normal distributions, affecting both means and standard deviations. Previous research suggests that z transformation may effectively correct mean bias for N's less than 30. In this study, simulations with small (20 and 30) and large (50 and 100) N's found that mean bias adjustments for larger N's are seldom needed. However, z transformations improved confidence intervals even for N = 100. The improvement was not in the estimated standard errors so much as in the asymmetrical CI's estimates based upon the z transformation. The resulting observed probabilities were generally accurate to within 1 point in the first non-zero digit. These issues are an order of magnitude less important for accuracy than design issues influencing the accuracy of the results, such as reliability, restriction of range, and N. DOI:10.2458/azu_jmmss_v1i2_gorsuch

scholarly journals Perceived and Real Aquatic Competence in Children from 6 to 10 Years Old

2020 ◽  
Vol 17 (17) ◽  
pp. 6101
Author(s):  
Aldo M. Costa ◽  
Alexandra Frias ◽  
Sandra S. Ferreira ◽  
Mario J. Costa ◽  
António J. Silva ◽  
...  
Keyword(s):  
Pearson Correlation ◽  
Age Groups ◽  
Correlation Coefficients ◽  
T Test ◽  
Simple Condition ◽  
Significance Level ◽  
Complex Condition ◽  
The Relationship ◽  
Two Age Groups ◽  
Breath Control

This study aimed to analyze the relationship between perceived aquatic competence (PAC) and real aquatic competence (RAC) in 6 to 10 year old children in skills identified as relevant for surviving an aquatic accident. The study sample consisted of 105 children (8.2 + 1.3 years old). Two age groups were examined separately [G1, 6 to 7 years (n = 53); G2, 8 to 10 years (n = 52)]. Children’s aquatic competence was evaluated twice for skills linked to the risk of drowning: Firstly, using a common swimsuit (simple condition) and secondly wearing a t-shirt (complex condition). The PAC was assessed by questionnaire interview. Pearson correlation coefficients, pairwise, and independent t-test comparisons were performed with a significance level of 5%. Similar levels of PAC were found among both age groups for all measured skills, excepted for breath control during swimming (p < 0.05). However, PAC differs significantly (p < 0.001) from RAC (in simple and complex conditions) only in G1. Correlations between PAC and RAC were modest for all measured skills in both age-groups. Significant differences were found between RAC in simple and complex conditions in both groups (p < 0.01). Age contributes to a higher perceived aquatic competence in skills related to the risk of drowning.

scholarly journals Educational Effect of Telegram-Based Virtual Training on Orthopedic Residents’ Knowledge in the Field of Spine Surgery

2020 ◽  
Vol 7 (2) ◽  
pp. 73-78
Author(s):  
Zahra Yahoueian ◽  
◽  
Mona Najaf Najafi ◽  
Reza Habibzadeh Shojaie ◽  
Seyed Mohammad Ata Sharifi Dalooei ◽  
...  
Keyword(s):  
Spine Surgery ◽  
Correlation Coefficients ◽  
T Test ◽  
Activity Level ◽  
Multiple Choice Questions ◽  
Virtual Training ◽  
Exact Test ◽  
Training Course ◽  
Level Of Knowledge ◽  
Case Presentations

Background: The widespread use of social networks among students seems to provide an appropriate opportunity to track the effects of the media on their educational capabilities. Objectives: We aimed to investigate the effect of virtual education (via Telegram messaging service during six months) on the knowledge of orthopedic residents of Mashhad University of Medical Sciences in the field of spine surgery. Methods: This quasi-experiment study was conducted on 25 orthopedic residents with an Mean±SD age of 31.4±4.1 years. During a 6-month training course, 85 educational spinal cases were presented in the form of riddles, video questions, or case presentations and were discussed among orthopedic residents. Before and after the intervention, a reliable and valid exam comprising 70 multiple choice questions about different topics of spinal surgery was taken to evaluate the level of students’ knowledge. We used the annual residency promotion exam to compare the correlation coefficients obtained by Fischer exact test, paired t test, and independent t test for statistical analysis. Results: The Mean±SD score of the assistants’ knowledge in the pretest and post-test exams were 42.8±6 and 45.2±9.2 (out of a total score of 70). Despite the obvious increase, the values were not statistically significant (P=0.09, t=-1.7). The intervention was associated with an increase in the level of knowledge in 17 residents (68%) while in 8 (32%), this 6-month virtual training course has had no significant effect. In this regard, age, marital status, housing, activity level, or level of residency (from the first to fourth year) had no significant relationship with knowledge improvement. Conclusion: virtual spinal education for six months using the social network of Telegram could improve the level of knowledge in most orthopedic residents, although the observed difference was not statistically significant.

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