scholarly journals Not p-Values, Said a Little Bit Differently

Econometrics ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 11 ◽  
Author(s):  
Richard Startz
Keyword(s):  
P Value ◽  
P Values ◽  
Numerical Examples ◽  
Practical Matter ◽  
The One

As a contribution toward the ongoing discussion about the use and mis-use of p-values, numerical examples are presented demonstrating that a p-value can, as a practical matter, give you a really different answer than the one that you want.

scholarly journals Time-Adaptive Statistical Test for Random Number Generators

Entropy ◽  
2020 ◽  
Vol 22 (6) ◽  
pp. 630 ◽  
Author(s):  
Boris Ryabko
Keyword(s):  
Random Number ◽  
Statistical Tests ◽  
Asymptotic Properties ◽  
Test Sequence ◽  
P Value ◽  
Specific Test ◽  
Random Number Generators ◽  
P Values ◽  
Small Deviations ◽  
The One

The problem of constructing effective statistical tests for random number generators (RNG) is considered. Currently, there are hundreds of RNG statistical tests that are often combined into so-called batteries, each containing from a dozen to more than one hundred tests. When a battery test is used, it is applied to a sequence generated by the RNG, and the calculation time is determined by the length of the sequence and the number of tests. Generally speaking, the longer is the sequence, the smaller are the deviations from randomness that can be found by a specific test. Thus, when a battery is applied, on the one hand, the “better” are the tests in the battery, the more chances there are to reject a “bad” RNG. On the other hand, the larger is the battery, the less time it can spend on each test and, therefore, the shorter is the test sequence. In turn, this reduces the ability to find small deviations from randomness. To reduce this trade-off, we propose an adaptive way to use batteries (and other sets) of tests, which requires less time but, in a certain sense, preserves the power of the original battery. We call this method time-adaptive battery of tests. The suggested method is based on the theorem which describes asymptotic properties of the so-called p-values of tests. Namely, the theorem claims that, if the RNG can be modeled by a stationary ergodic source, the value − l o g π ( x 1 x 2 … x n ) / n goes to 1 − h when n grows, where x 1 x 2 … is the sequence, π ( ) is the p-value of the most powerful test, and h is the limit Shannon entropy of the source.

Explorations in statistics: hypothesis tests and P values

2009 ◽  
Vol 33 (2) ◽  
pp. 81-86 ◽  
Author(s):  
Douglas Curran-Everett
Keyword(s):  
Null Hypothesis ◽  
P Value ◽  
Test Statistics ◽  
Simple Test ◽  
Hypothesis Tests ◽  
Test Statistic ◽  
P Values ◽  
The One

Learning about statistics is a lot like learning about science: the learning is more meaningful if you can actively explore. This second installment of Explorations in Statistics delves into test statistics and P values, two concepts fundamental to the test of a scientific null hypothesis. The essence of a test statistic is that it compares what we observe in the experiment to what we expect to see if the null hypothesis is true. The P value associated with the magnitude of that test statistic answers this question: if the null hypothesis is true, what proportion of possible values of the test statistic are at least as extreme as the one I got? Although statisticians continue to stress the limitations of hypothesis tests, there are two realities we must acknowledge: hypothesis tests are ingrained within science, and the simple test of a null hypothesis can be useful. As a result, it behooves us to explore the notions of hypothesis tests, test statistics, and P values.

scholarly journals Three Insights from a Bayesian Interpretation of the One-Sided P Value

2016 ◽  
Vol 77 (3) ◽  
pp. 529-539 ◽  
Author(s):  
Maarten Marsman ◽  
Eric-Jan Wagenmakers
Keyword(s):  
Statistical Models ◽  
Null Hypothesis ◽  
Posterior Probability ◽  
P Value ◽  
P Values ◽  
Inferential Method ◽  
Point Null Hypothesis ◽  
Probability Mass ◽  
The One ◽  
Size Variable

P values have been critiqued on several grounds but remain entrenched as the dominant inferential method in the empirical sciences. In this article, we elaborate on the fact that in many statistical models, the one-sided P value has a direct Bayesian interpretation as the approximate posterior mass for values lower than zero. The connection between the one-sided P value and posterior probability mass reveals three insights: (1) P values can be interpreted as Bayesian tests of direction, to be used only when the null hypothesis is known from the outset to be false; (2) as a measure of evidence, P values are biased against a point null hypothesis; and (3) with N fixed and effect size variable, there is an approximately linear relation between P values and Bayesian point null hypothesis tests.

Efektifitas Ekstrak Daun Sirih Hijau (Piper Betle) sebagai Insektisida Nabati terhadap Mortalitas Lalat Rumah (Musca domestica)

2019 ◽  
Vol 10 (2) ◽  
pp. 44-50
Author(s):  
Rinaldi Daswito ◽  
Rima Folentia ◽  
M Yusuf MF
Keyword(s):  
Musca Domestica ◽  
Leaf Extract ◽  
Effective Concentration ◽  
P Value ◽  
Piper Betle ◽  
Microbiology Laboratory ◽  
House Flies ◽  
Betel Leaf ◽  
The One ◽  
One Way Anova

One of the diseases that can be transmitted by flies is diarrhea. Green betel leaf contains essential oils, chavicol, arecoline, phenol, and tannins which function as plant-based insecticides. This study aimed to determine the effectiveness of green betel leaf extract (Piper betel) as a plant-based insecticide on the number of mortality of house flies (Musca domestica). The research was an experimental study used After Only Design used the One Way Anova test with a 95% confidence level. The samples used were 360 ​​house flies. Each treatment of 30 house flies with 4 repetitions and used three concentrations of green betel leaf extract (25%, 50%, 75%). The study was conducted at the Chemistry and Microbiology Laboratory of Health Polytechnic Tanjungpinang, while the location of the fly collection was at the Tokojo Garbage Collection Station in Bintan Regency. The number of mortality of house flies at a concentration of 25% was 81 heads (67.5%), 50% concentrations were 93 heads (77.5%), and at a concentration of 75% were 103 heads (85.83%). There was an effect of green betel leaf extract on the mortality of house flies (p-value 0.0001 <0.05) with the most effective concentration of 75%. Further research is needed to obtain a finished product utilizing green betel leaf extract as a vegetable insecticide, especially in controlling the fly vector. Need further research on the use of green betel leaf extract as a vegetable insecticide controlling the fly vector by taking into account the amount of spraying and the age of the fly.   Keywords: Green betel leaf extract , organic insecticide, houseflies

scholarly journals Comparison of Four Commercially Available Point-of-Care Tests to Detect Antibodies against Canine Parvovirus in Dogs

Viruses ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 18
Author(s):  
Michèle Bergmann ◽  
Mike Holzheu ◽  
Yury Zablotski ◽  
Stephanie Speck ◽  
Uwe Truyen ◽  
...  
Keyword(s):  
Test Performance ◽  
Point Of Care ◽  
Reference Method ◽  
Canine Parvovirus ◽  
P Value ◽  
Important Indicator ◽  
Specificity And Sensitivity ◽  
Specific Pathogen ◽  
The One ◽  
Point Of Care Tests

Measuring antibodies to evaluate dogs´ immunity against canine parvovirus (CPV) is useful to avoid unnecessary re-vaccinations. The study aimed to evaluate the quality and practicability of four point-of-care (POC) tests for detection of anti-CPV antibodies. The sera of 198 client-owned and 43 specific pathogen-free (SPF) dogs were included; virus neutralization was the reference method. Specificity, sensitivity, positive and negative predictive value (PPV and NPV), and overall accuracy (OA) were calculated. Specificity was considered to be the most important indicator for POC test performance. Differences between specificity and sensitivity of POC tests in the sera of all dogs were determined by McNemar, agreement by Cohen´s kappa. Prevalence of anti-CPV antibodies in all dogs was 80% (192/241); in the subgroup of client-owned dogs, it was 97% (192/198); and in the subgroup of SPF dogs, it was 0% (0/43). FASTest® and CanTiCheck® were easiest to perform. Specificity was highest in the CanTiCheck® (overall dogs, 98%; client-owned dogs, 83%; SPF dogs, 100%) and the TiterCHEK® (overall dogs, 96%; client-owned dogs, 67%; SPF dogs, 100%); no significant differences in specificity were observed between the ImmunoComb®, the TiterCHEK®, and the CanTiCheck®. Sensitivity was highest in the FASTest® (overall dogs, 95%; client-owned dogs, 95%) and the CanTiCheck® (overall dogs, 80%; client-owned dogs, 80%); sensitivity of the FASTest® was significantly higher compared to the one of the other three tests (McNemars p-value in each comparison: <0.001). CanTiCheck® would be the POC test of choice when considering specificity and practicability. However, differences in the number of false positive results between CanTiCheck®, TiterCHEK®, and ImmunoComb® were minimal.

scholarly journals SAT0210 FACTORS ASSOCIATED WITH TIME TO SEVERE LUPUS NEPHRITIS IN A COHORT OF COLOMBIAN PATIENTS

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1048.2-1048
Author(s):  
S. Herrera ◽  
J. C. Diaz-Coronado ◽  
D. Rojas-Gualdrón ◽  
L. Betancur-Vasquez ◽  
D. Gonzalez-Hurtado ◽  
...  
Keyword(s):  
Lupus Nephritis ◽  
Renal Involvement ◽  
Classification Criteria ◽  
P Value ◽  
Systemic Lupus ◽  
P Values ◽  
Interval Censored ◽  
Severe Lupus Nephritis ◽  
Age And Sex

Background:Systemic lupus erythematosus (SLE) clinical manifestations, and their severity, vary according to age, ethnicity and socioeconomic status. Both Hispanic and Afro-Americans have a higher incidence and more sever presentation when compared to Caucasian patients with SLEObjectives:To analyze clinical and immunological characteristics associated with time to severe renal involvement in patients with Systemic Lupus Erythematous in a Colombian cohort followed for one year, between January 2015 and December 2018Methods:Retrospective follow-up study based in clinical records. Patients with SLE diagnosis that fulfilled either 1987 American College of Rheumatology Classification Criteria for SLE or 2011 Systemic Lupus International Collaborating Clinics (SLICC) classification criteria for SLE. We included patients with diagnosis of lupus nephritis according to Wallace and Dubois criteria. Patients who did not have at least two follow-up measurements or had a cause of nephritis other than lupus were excluded. The main outcome was defined as time from diagnosis to sever renal involvement defined as creatinine clearance ≤50 ml/min, 24-hour proteinuria ≥3.5 grams o end stage renal disease.We analyzed clinical and immunological characteristics. Descriptive statistical analyses of participant data during the first evaluation are reported as frequencies and percentages for categorical variables, and as medians and interquartile ranges (IQR) for quantitative variables. Age and sex adjusted survival functions and Hazard ratios (HR) with 95% confidence intervals and p-values were estimated using parametric Weibull models por interval-censored data. P values < 0.05 were considered statistically significantResults:548 patients were analyzed: 67 were left-censored as they presented renal involvement at entry, 6 were interval censored as outcome occurred between study visits, and 475 were right-censored as involvement was not registered during follow-up. 529 (96.5%) patients were female, median age at entry was 46 (IQR = 23) and median age to diagnosis was 29.5 (IQR = 20.6). 67% were mestizo, 13% Caucasian and 0.3% Afro-Colombian. Age and sex adjusted variables associated with time to severe lupus nephritis were high blood pressure HR = 3.5 (95%CI 2.2-5.6; p-value <0.001) and Anti-RO (per unit increase) HR = 1.002 (95%CI 1.001-1.004; p-value = 0.04). Figure 1 shows age and sex adjusted survival function.Conclusion:In our cohort the appearance of severe lupus nephritis occurs in less than 15% of patients at 10 years. Both high blood pressure and elevated anti-Ro titers were associated with a higher rate of onset in the presentation of severe lupus nephritis, as seen in some polymorphs of anti Ro.References:Disclosure of Interests:Sebastian Herrera Speakers bureau: academic conference, Juan camilo Diaz-Coronado: None declared, Diego Rojas-Gualdrón: None declared, Laura Betancur-Vasquez: None declared, Daniel Gonzalez-Hurtado: None declared, Juanita Gonzalez-Arango: None declared, laura Uribe-Arango: None declared, Maria Fernanda Saavedra Chacón: None declared, Jorge Lacouture-Fierro: None declared, Santiago Monsalve: None declared, Sebastian Guerra-Zarama: None declared, Juan david Lopez: None declared, Juan david Serna: None declared, Julian Barbosa: None declared, Ana Sierra: None declared, Deicy Hernandez-Parra: None declared, Ricardo Pineda.Tamayo: None declared

NO EVIDENCE, OR NOT ENOUGH EVIDENCE?

PEDIATRICS ◽  
1996 ◽  
Vol 98 (6) ◽  
pp. A22-A22
Author(s):  
Student
Keyword(s):  
Confidence Intervals ◽  
P Value ◽  
P Values ◽  
Considerable Uncertainty ◽  
Absence Of Evidence

When we are told that "there's no evidence that A causes B," we should first ask whether absence of evidence means simply that there is no information at all. If there are data, we should look for quantification of the association rather than just a P value. Where risks are small, P values may well mislead: confidence intervals are likely to be wide, indicating considerable uncertainty.

The Effectiveness of Durante Hemodialysis Packed Red Cells (PRC) Transfusion on Hemoglobin Levels

2021 ◽  
Vol 8 (1) ◽  
pp. 013-018
Author(s):  
Pria Wahyu Romadhon Girianto ◽  
Mega Wahyu Mulyasari
Keyword(s):  
Renal Disease ◽  
Chronic Renal Disease ◽  
Statistical Tests ◽  
Health Condition ◽  
P Value ◽  
Test Design ◽  
Significance Level ◽  
Study Results ◽  
Post Test ◽  
The One

Renal Disease was a chronic disease that the most attacking people in Indonesia. Damage to this vital organ in the human body greatly affected a person's health condition, one of which was anemia. This study aimed to determine the effectiveness of Durante hemodialysis PRC transfusions on hemoglobin levels. The method used was Pre-experimental design, with the One group pre-post test design approach. With a sample of 49 patients who underwent regular hemodialysis at RSUD dr. Iskak Tulungagung. Data were obtained by direct observation. Processed by computerized methods with a statistical t-test, the significance level (α) was 0.05. The study results showed that the hemoglobin levels of the pre-Durante hemodialysis PRC transfusion patients were 4-5 mg/dl (53.06%), and the hemoglobin levels of the post-Durante hemodialysis PRC transfusion patients were 6.1-7 mg/dl (34.69%). The results of statistical tests showed that there was an increase in hemoglobin levels in patients who received Durante hemodialysis PRC transfusion by 1.22 mg/dl because p-value = 0.000 < 0.05 (α) means that there was an effect. It could be concluded that the delivery of Durante hemodialysis PRC transfusion could help increase hemoglobin levels. This finding was very helpful for chronic Renal Disease patients undergoing hemodialysis, who have been using erythropoietin preparations because PRC transfusions were cheaper and more effective when compared to using erythropoietin preparations

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