Is the assessment of interlaboratory comparison results for a small number of tests and limited number of participants reliable and rational?

Szewczak, E; Bondarzewski, Adam

doi:10.1007/s00769-016-1195-y

Cited by 23 publications

(21 citation statements)

References 7 publications

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“…There are no reference materials and it is impossible to repeat a test on the same item because it is destroyed. This reduces possibilities to draw conclusions about the laboratory uncertainty based on the results of inter-laboratory comparisons [19]. Therefore, laboratories are usually condemned to rely on their own, simplified analysis of uncertainty.…”

Section: Methods For the Evaluation Of Results Variabilitymentioning

confidence: 99%

Performance evaluation of the construction products as a research challenge. Small error – big difference in assessment?

Szewczak

Piekarczuk

2016

Bulletin of the Polish Academy of Sciences Technical Sciences

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Abstract. The paper refers to the importance of test results uncertainty in the assessment of the construction product performance. Uncertainty understood as dispersion attributed to any value which is result of the tests, calculations or other evaluations, occurs at every level of assessment (material, product, construction). Authors presented the various approaches to uncertainty estimation, especially in situation of small number of tests results which is characteristic for testing of construction products. Effects of uncertainty on final assessment of construction product was analyzed using the example of bearing capacity of thin-walled structure obtained by numerical calculation. Different values of material tests uncertainty resulting from different approaches to its assessment was taken into account. It was demonstrated that the difference in the results of strength tests of a material, which falls within the limits of uncertainty, may result in a very significant difference in the evaluation of a structure.Key words: uncertainty, numerical calculation, uncertainty influence on product assessment. Each value resulting from tests may only be considered in terms of probability. Unfortunately, in a small number of cases it is possible to express this probability using a probability density function (PDF) which is characterised by the expectation value and standard deviation (SD). In all tests which yield qualitative results (ordinal scale with two categories e.g. "fulfilled", "not fulfilled") or semi-quantitative results (ordinal scale with more than two categories), which, in the authors' opinion, are the majority of tests to which construction products are subjected, the determination of a PDF is an issue requiring extensive inter-laboratory tests performed on repeatable items [5][6][7]. Usually this is not possible for tests on construction products.Linking a value being measured with a PDF that is assigned to it is much easier for quantitative methods, for which the estimation of the uncertainty of a test result, allowing one to provide a PDF, is subject to numerous guidelines and instructions. The basic principles have been developed by the Joint Committee for Guides in Metrology [8], and are commonly applied by virtually all laboratories. However, as will be demonstrated for destructive (e.g. mechanical) testing, the estimation of uncertainty may be associated with numerous ambiguities.Presented by Walker et al. [9] typology and terminology of harmonized uncertainty provide uncertainity identification by location, including inter alia parameter uncertainty (associated with the variability of input data) and model uncertainty (associated also, but not only with lack of sufficient understanding of the system). These two kind of uncertainty sources are presented in test results and in estimation of uncertainty of the test results (uncertainty of estimated uncertainty). Variability relating to laboratory testing results has many components. Some of them, e.g. metrological parameters of testing equipment, ...

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Section: Methods For the Evaluation Of Results Variabilitymentioning

confidence: 99%

Performance evaluation of the construction products as a research challenge. Small error – big difference in assessment?

Szewczak

Piekarczuk

2016

Bulletin of the Polish Academy of Sciences Technical Sciences

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“…We should pay special attention here to the aspect of credibility -that is the uncertainty which may accompany the result [7], and, therefore, the number of repetitions or sampling [8] and, consequently, the cost of the assessment. In general, heterogeneous products are used in construction.…”

Section: Czarnecki and D Van Gemert Scientific Basis And Rules Ofmentioning

confidence: 99%

Scientific basis and rules of thumb in civil engineering: conflict or harmony?

Czarnecki

Gemert

2016

Bulletin of the Polish Academy of Sciences Technical Sciences

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Abstract. Science and engineering intermingle in the area of construction. Engineering works, often of great dimensions and design life cycle of many decades, have to be designed on a scientific basis since the safety of hundreds of users depends on their design. The task of scientific institutions is to define the construction performance within categories that correspond to the contemporary level of knowledge and technology. A construction appraiser who speaks out in a way that ensures unquestionable competence about the performance of elements and buildings (existing and under construction), should be convinced of the scientific basis of his opinions. A comparison of construction sections vs. basic requirements presents an archetype of the science of construction. A matrix of the science of construction reveals its multi-faceted nature; if related to time -the issue of durability has to be considered, and if related to the scale -the complexity. Defining the construction performance in terms of technical features is a constant search for a relationship between the material model and the usability model of a building. The construction industry uses a lot of "rules of thumb", more than any other sector of technology. In the era of computer-aided design, CAD, and building information modelling (BIM), those rules of thumb remain invaluable verification tools.Key words: building performance, appraiser, matrix of the science of construction, rules of thumb, durability, complexity, diversified development. Scientific basis and rules of thumb in civil engineering Defining building performanceThe primary task of universities and research institutes in the scientific discipline of construction is to continuously define building performance in a manner consistent with the current level of knowledge and technology. This means permanently seeking true solutions [2] -the relationship between the two corresponding models [3]: the material model (material model is used here to represent materials, analyses and geometries) and the usability model, which combines properties and requirements (Fig. 1).

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“…The major advantage of harmonized test results in laboratory assays include the use of common decision limits specified in clinical guidelines across all methods and the uniform interpretation of results [ 20 , 21 , 22 , 23 ]. Several studies have investigated or proposed strategies to compare inter-laboratory results and assess variation using certified reference materials (e.g., PT and QC materials) in combination with a reference laboratory [ 24 , 25 , 26 , 27 ]. Recent work demonstrated that QC samples could be used to standardize MS results across laboratories using the same extraction protocol and type of mass spectrometer [ 28 ].…”

Section: Introductionmentioning

confidence: 99%

Harmonizing Newborn Screening Laboratory Proficiency Test Results Using the CDC NSQAP Reference Materials

Pickens

Sternberg

Seeterlin

et al. 2020

IJNS

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Newborn screening (NBS) laboratories cannot accurately compare mass spectrometry-derived results and cutoff values due to differences in testing methodologies. The objective of this study was to assess harmonization of laboratory proficiency test (PT) results using quality control (QC) data. Newborn Screening Quality Assurance Program (NSQAP) QC and PT data reported from 302 laboratories in 2019 were used to compare results among laboratories. QC materials were provided as dried blood spot cards which included a base pool and the base pool enriched with specific concentrations of metabolites in a linear range. QC data reported by laboratories were regressed on QC data reported by the Centers for Disease Control and Prevention (CDC), and laboratory’s regression parameters were used to harmonize their PT result. In general, harmonization tended to reduce overall variation in PT data across laboratories. The metabolites glutarylcarnitine (C5DC), tyrosine, and phenylalanine were displayed to highlight inter- and intra-method variability in NBS results. Several limitations were identified using retrospective data for harmonization, and future studies will address these limitations to further assess feasibility of using NSQAP QC data to harmonize PT data. Harmonizing NBS data using common QC materials appears promising to aid result comparison between laboratories.

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Is the assessment of interlaboratory comparison results for a small number of tests and limited number of participants reliable and rational?

Cited by 23 publications

References 7 publications

Performance evaluation of the construction products as a research challenge. Small error – big difference in assessment?

Performance evaluation of the construction products as a research challenge. Small error – big difference in assessment?

Scientific basis and rules of thumb in civil engineering: conflict or harmony?

Harmonizing Newborn Screening Laboratory Proficiency Test Results Using the CDC NSQAP Reference Materials

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