Reconsideration of the derivation of Most Probable Numbers, their standard deviations, confidence bounds and rarity values
Reconsideration of the derivation of Most Probable Numbers, their standard deviations, confidence bounds and rarity values
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DOI：
10.1111/j.1365-2672.2010.04792.x
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发表时间：
2010-11-01
影响因子：
4
通讯作者：
Wilrich, P. -T.
中科院分区：
文献类型：
--
作者：
Jarvis, B.;Wilrich, C.;Wilrich, P. -T.
目的：这项工作的目的是推导出一个简单的Excel电子表格和一组标准表的最可能数（MPN）值，可以由国际标准方法的用户应用，以获得相同的输出值的MPN，SD的MPN，95%的置信限和测试有效性。对于后者，它被认为是Blodgett的概念的“稀有性”是更有价值的比经常使用的方法的不可能性（见德的人）。方法和结果：本文介绍了在工作中使用的统计程序和引入一套新的概念和实际的方法来确定MPN及其参数的原因。使用这些程序得出的MPN的例子。Excel电子表格可从http://www.wiwiss.fu-berlin.de/institute/iso/mitarbeiter/wilrich/index.html.Conclusions:The下载。应用经修订的方法确定MPN参数，允许那些希望使用表格值的人以及那些需要访问简单电子表格以确定非标准测试协议值的人获得任何特定的多个测试结果集的相同输出值。“稀有度”的概念是一个更容易理解的参数，用于描述统计学上无效的测试结果组合。提供的SD的对数MPN值允许推导的不确定性参数，以前是不可能的。意义和影响的研究：一个一致的方法推导的MPN及其参数是必不可少的国际标准方法之间的一致性。未来的微生物学标准方法将基于本文所述的程序。
Aims:The purpose of this work was to derive a simple Excel spreadsheet and a set of standard tables of most probable number (MPN) values that can be applied by users of International Standard Methods to obtain the same output values for MPN, SD of the MPN, 95% confidence limits and test validity. With respect to the latter, it is considered that the Blodgett concept of 'rarity' is more valuable than the frequently used approach of improbability (vide de Man).Methods and Results:The paper describes the statistical procedures used in the work and the reasons for introducing a new set of conceptual and practical approaches to the determination of MPNs and their parameters. Examples of MPNs derived using these procedures are provided. The Excel spreadsheet can be downloaded from http://www.wiwiss.fu-berlin.de/institute/iso/mitarbeiter/wilrich/index.html.Conclusions:The application of the revised approach to the determination of MPN parameters permits those who wish to use tabulated values, and those who require access to a simple spreadsheet to determine values for nonstandard test protocols, to obtain the same output values for any specific set of multiple test results. The concept of 'rarity' is a more easily understood parameter to describe test result combinations that are not statistically valid. Provision of the SD of the log MPN value permits derivation of uncertainty parameters that have not previously been possible.Significance and Impact of the Study:A consistent approach for the derivation of MPNs and their parameters is essential for coherence between International Standard Methods. It is intended that future microbiology standard methods will be based on the procedures described in this paper.