• 제목/요약/키워드: null hypothesis

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치의학 연구에서 귀무가설 유의성 검정의 문제점과 대안에 관한 고찰 (Review on Problems with Null Hypothesis Significance Testing in Dental Research and Its Alternatives)

  • 이광희
    • 대한소아치과학회지
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    • 제40권3호
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    • pp.223-232
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    • 2013
  • 치의학 연구에서 사용되는 귀무가설 유의성 검정에서 p값을 기준으로 연구의 결과를 평가하는 것은 많은 문제점을 내포하고 있다. 귀무가설이 기각되지 않은 경우에 귀무가설이 옳다는 결론을 내리는 것은 논리적 오류이다. p값에 대한 중대한 오해가 많이 있으며 연구자는 논문을 작성할 때 p값의 해석에 신중해야 한다. 귀무가설검정을 보완하거나 대체할 수 있는 대안으로서, 효과 크기, 신뢰구간, 베이지안 통계 등이 있다.

AESA 레이더 최대탐지거리의 통계적 접근 (Statistical Approach for AESA Radar Maximum Detection Range)

  • 탁대석;신경수
    • 시스템엔지니어링학술지
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    • 제15권1호
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    • pp.43-50
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    • 2019
  • Statistical hypothesis tests are important for quantifying answers to questions about samples of data. The Step Process of Statistical Hypothesis Testing; state the null hypothesis, State the alternate hypothesis, State the alpha level, Find the z-score associated with alpha level, Find the test statistic using this formula, If the calculated t distribution value from the data is larger than the t distribution value of alpha level, then you are in the Rejection region and you can reject the Null Hypothesis with ($1-{\alpha}$) level of confidence.

A Study on Goodness-of-fit Test for Density with Unknown Parameters

  • Hang, Changkon;Lee, Minyoung
    • Communications for Statistical Applications and Methods
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    • 제8권2호
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    • pp.483-497
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    • 2001
  • When one fits a parametric density function to a data set, it is usually advisable to test the goodness of the postulated model. In this paper we study the nonparametric tests for testing the null hypothesis against general alternatives, when the null hypothesis specifies the density function up to unknown parameters. We modify the test statistic which was proposed by the first author and his colleagues. Asymptotic distribution of the modified statistic is derived and its performance is compared with some other tests through simulation.

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임상연구방법론에서 귀무가설과 대립가설, 귀류법에 대한 고찰과 한방이비인후과에서 베이지안 통계학의 활용 (A Study on Null Hypothesis and Alternative Hypothesis, Reduction to Absurdity and Application of Bayesian Statistics in Korean Medicine Otolaryngology)

  • 남승표;배재민;권강
    • 한방안이비인후피부과학회지
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    • 제32권4호
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    • pp.41-61
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    • 2019
  • Background : The current medical statistics used in clinical research are the results of Fisher's significance test and the Neyman-Pearson hypothesis test, which were combined by psychologists. Also, in the philosophical background, it is related to Popper's falsificationism based hypothesis-deductive method and reduction to absurdity. Objectives : This study was designed to find complementary and alternative methods of null hypothesis and alternative hypothesis used for the clinical research methodology of Korean medicine otolaryngology. Methods : The body of this paper was divided into seven part. These are historical background, hypothesis test, hypothesis test method used in the design of clinical study, falsificationism and reduction to absurdity, problem and alternative method of the Neyman-Pearson hypothesis test, diagnosis example of sinusitis differentiation syndromes by Bayesian statistics. Through this process, we found out problems of frequentist statistics and suggested alternative methods. Result & Conclusion : As a solution to the problems of the null hypothesis and the alternative hypothesis, there are effects size, confidence interval, Bayesian statistics and Lakatos methodology of scientific research programmes.

Robustness of Bayes Test on Dependent Sample

  • Oh, Hyun-Sook
    • Communications for Statistical Applications and Methods
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    • 제4권3호
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    • pp.787-793
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    • 1997
  • It is well known that the assumption of independence is ofter not valid for real data. This phenomenon has been observed empirically by many prominent scientists. In this article the sensitivity of dependence on Bayes test of a sharp null hypothesis is considered. The robustness is considered with respect to the significant level and the prior probability on the null hypothesis.

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Multivariate Analysis of Variance for Fuzzy Data

  • Kang, Man-Ki;Han, Sung-Il
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제4권1호
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    • pp.97-100
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    • 2004
  • We propose some properties of fuzzy multivariate analysis of variance by fuzzy vector operation with agreement index. We deals fuzzy null hypotheses and fuzzy alternative hypothesis and define the agreement index for the grades of the judgements that the hypothesis is rejection or acceptance. Finally, we provide an example to evaluate the judgements.

Influence Functions on $ {\chi}^2$ Statistic in Contingency Tables

  • Honggie Kim;Hee-Sook Lee
    • Communications for Statistical Applications and Methods
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    • 제3권2호
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    • pp.69-76
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    • 1996
  • In a two-way contingency table, the analyst is most interested in the hypotheses of either homogeneity or independence. For testing this as a null hypothesis, Pearson's ${\chi}^2$ statistic is most commonly used in practice. Once the null Hypothesis is rejected, he will further search forcells which caused the rejection of the null hypothesis. For this purpose, so called cell${\chi}^2$ components are used. In this paper, we derive the influence function of an obsevation to the ${\chi}^2$ statistic, with which cells with high influence can be identified.

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고속도로 터널 내 화재사고 발생 시 대피행동 지연 요인에 관한 연구 (A Study on the Delayed Factors in Evacuation Behavior in the Case of Fire Accidents in Highway Tunnels)

  • 조재환
    • 대한안전경영과학회지
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    • 제24권4호
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    • pp.143-148
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    • 2022
  • This paper attempted to analyze the correlation between the risk image of the evacuees in the tunnel and the variables that affect the evacuation behavior due to the closed feeling. As to whether there is a difference in the level of recognizing the tunnel risk image according to the distribution of jobs, the null hypothesis was rejected at the significance probability of 0.002, so it can be said that the level of recognition of the tunnel risk image varies depending on the job group. In the distribution difference between gender and tunnel risk image recognition level, the significance probability was 0.012, indicating that the null hypothesis was rejected, indicating that the tunnel risk recognition distribution according to gender was different. As a result of analyzing the distribution difference between the tunnel's closed feeling and the tunnel risk perception level, the significance probability was 0.001, and the null hypothesis was rejected, indicating that there was a difference in the tunnel risk image level.

On Sample Size Calculation in Bioequivalence Trials

  • Kang, Seung-Ho
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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    • pp.90-90
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    • 2003
  • Sample size calculations play an important role in bioequivalence trials. In almost all clinical trials sample size is determined by considering power under the alternative hypothesis. The alternative hypothesis is the hypothesis that we wish to prove with experiments. Hence, in bioequivalence trials the alternative hypothesis is that two formulations are bioequivalent, while the null hypothesis is that the two formulations are not bioequivalent. (omitted)

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분산분석을 활용한 K11 복합형소총 사격통제장치 균열발생 원인 연구 (A Study on Crack Formation in the K11 Objective Individual Combat Weapon Fire Control System using Analysis of Variance)

  • 신상식;김병규;심철보
    • 품질경영학회지
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    • 제43권3호
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    • pp.289-298
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    • 2015
  • Purpose: This study examined the problem of crack formation in the fire control system(FCS) of the K11 objective individual combat weapon(OCIW), using design of experiment analysis. Three hypothesis were considered. The first hypothesis is that bolted joint has an effect on impulse caused by firing the weapon and the second hypothesis is that a short time interval of shooting has an effect on impulse and lastly, the third hypothesis is that a positive correlation has between the bolted joint of the FCS and the impulse. Methods: The relationship between the bolted joint and the impulse cause by firing the weapon were examined experimentally. The first and second hypothesis was tested using correlation analysis and the t-test. Results: Using ANOVA, the first null hypothesis was rejected and the alternative hypothesis was accepted. ANONA confirmed the second null hypothesis. Correlation analysis dismissed the last null hypothesis. A positive correlation between the bolted joint and the impulse caused by shooting the weapon was verified. Conclusion: The bolted joint of the K11 FCS and the barrel of the K11 affect the impulse caused by firing the weapon. A positive correlation was established between the bolted joint of the FCS and the impulse on firing the K11 OICW.