Intermediate precision defined

Intermediate precision, defined as the closeness of agreement between individual test results obtained with the same method on identical test material but in one laboratory, where operator and/or equipment and/or time are changed. 

Fig. 6. A fault tree for the pumped storage example of Figure 5. For a real system the tank and pump failures would be more precisely defined, or set as intermediate events having further definition by subsequent basic events and more detailed failure modes.

Precision studies can be planned in a full factorial matrix-type format involving multiple analysts, days, capillaries, buffer preparations, instruments, etc. Table 9 displays an example matrix for intermediate precision testing involving two analysts, two instruments, and two capillaries over a multiple day period. Typically, qualification targets for acceptable precision will be pre-defined based on method type, capability, and intent. Acceptable targets can also be mathematically determined by the method of Horwitz. ... 

Two types of precision are usually distinguished, namely the repeatability and the reproducibility. Repeatability is the precision obtained in the best possible circumstances (same analyst, one instrument, within one day when possible) and reproducibility under the most adverse possible circumstances (different laboratories, different analysts, different instruments, longer periods of time, etc.). Reproducibility can be determined only with interlaboratory experiments. Intermediate situations may and do occur. They are for instance defined in terms of M-factor-different intermediate precision measures, where M is one, two, three or even higher [8,9]. In this definition M refers to the number of factors that are varied to make the estimation. The most likely factors to be varied are time, analyst and instrument. According to this terminology, one estimates e.g. the time-and-analyst-different intermediate precision measure (M=2), when the precision is determined by measuring a sample over a longer period of time in one laboratory by two analysts with one instrument. 

Intermediate Precision Intermediate precision is defined as the variation within the same laboratory. The extent to which intermediate precision needs to be estab-... 

Depending on the use of the assay, different parameters will have to be measured during the assay validation. Validation of analytical assays is the process of establishing one or more of the following as appropriate to the type of assay accuracy precision (repeatability, intermediate precision), linearity, range, limit of detection, limit of quantification, specificity, and robustness [1]. For physicochemical methods there are accepted defined limits for these test parameters ... 

Intermediate precision is defined as the long-term variability of the measurement process and is determined by comparing the results obtained when a method is run within a single laboratory over a number of days. Intermediate precision may reflect discrepancies in the results obtained by different operators, from different instruments, with different sources of reagents, with multiple lots of... 

Define the following terms instrument precision, injection precision, intra-assay precision, ruggedness, intermediate precision, and interlaboratory precision. 

Intermediate precision is a term that has been defined by ICH [3] as the long-term variability of the measurement process and is determined by compar-... 

Symmetry-adapted d orbitals can sometimes be specified in advance, so that the dimensionality of the matrix can be precisely defined by the degeneracy of the d orbitals. Then, and in intermediate symmetries, there may indeed be redundancy in the potential matrix. This might be uncovered by inspection. For example, when eoA = effB and ezA = ezB = 0, and a = 0 but p is nonzero, matrix M4 above for trans-M(A-A)2B2 assumes the form... 

The ICH has broadened and redefined these terms to more accurately describe the method s ability to reproducibly generate analytical results. Precision is defined as a combination of repeatability, intermediate precision, and reproducibility. Repeatability is system precision, as defined previously. Intermediate precision includes multiple analyses by multiple analysts on different days using different equipment within a given laboratory. This is only the first step in demonstrating the ruggedness of the method. 

The precision has been defined in the ISO 5725-1 standard as the closeness of agreement between independent test results obtained under stipulated conditions [28]. Many factors may contribute to the variability of test results obtained with the same method on identical samples, including (but not limited to) the operators), the equipment, the reagents, the RM(s), the environment, the time between measurements, and the laboratories. The maximal variability of test results is explained by the reproducibility (R) of the method. All factors that have influence on the variability of a test method should be taken into consideration when assessing the reproducibility. The repeatability (r) is assessed by keeping all the above-mentioned factors constant (e.g., same operator, same equipment, same laboratory, short time interval). It is a measure of the minimum variability of a method. The intermediate precision is situated between the two extreme measures of precision repeatability and reproducibility. The terms within-laboratory reproducibility (w), long-term precision, and so on, are often used to demonstrate the intermediate precision of a method. For a correct interpretation of the intermediate precision, the factors that have been taken into account should be known. 

The crystal symmetry of most organic metals is low, often only monoclinic, and the principal axes of the conductivity tensor (cr) are not precisely defined. However, in practice the conductivity along the chain direction (cr,) is particularly high, usually 300 to 2500 (Q-cm) 1 at room temperature, while that in one direction perpendicular to the chains (07) is very low [2]. Therefore, these two directions must be very close to the principal axes of ex. The third perpendicular direction has intermediate conductivity (07). So in the situation, where > 07, which is quite common, the principal axes of the conductivity and resistivity (p) tensors are known reasonably well. When measuring these quantities on a single crystal, care must be taken either to ensure that the current distribution is uniform, or alternatively, special methods such as those of Montgomery [11] or van der Pauw [12] must be used. Some insight into these problems can be obtained by consideration of the equivalent isotropic sample [11,13]. 

Precision results obtained under some well defined conditions are normally expressed as repeatability, reproducibility or intermediate precision. 

Ruggedness. The United States Pharmacopeia (USP) defines ruggedness as the degree of reproducibility of test results obtained by the analysis of the same samples under a variety of normal test conditions, such as different labs, different analysts, different lots of reagents,. Ruggedness is a measure of reproducibility of test results under normal, expected operational conditions from laboratory to laboratory and from analyst to analyst. See Intermediate precision. 

Precision of the method is defined by the sum of intermediate precision (interday, interoperator, and interassay precision) and repeatability. 

Precision components are defined at three levels reproducibility, intermediate precision, and repeatability. Reproducibility is the variability of the method between laboratories or facilities. However, as a laboratory is not randomly selected from a large population of facilities, laboratory is a fixed effect. Consequently, the assessment of reproducibility is a question of comparing the average results between laboratories. Additionally, the variation observed within laboratory should be compared to ensure that laboratory does not have an effect either on the average result of the method or on the variability of the method. To assess reproducibility, conduct the same set of validation experiments within each laboratory and compare both the accuracy results and the precision results. If the differences are meaningful, analysis of variance (ANOVA) tests can be conducted to determine whether there is a statistically significant laboratory effect on the mean or on the variance of the method. For simplicity, the validation discussed within this chapter will not consider reproducibility and only one laboratory is considered. 

Precision defines the scatter of repeated analysis, or the coefficient of variation of analytical results. Both intra-assay and inter-assay precision must be investigated. Intermediate precision describes the influence of different analysts, equipment, days and other intra-laboratory variabihty. Inter-laboratory comparison is also of interest in establishing the precision of the method. AU testing on accuracy and precision must be carried out by replicate analyses of a statistically relevant number of samples. Depending on the use of the method, it may be necessary to estabhsh both parameters over the measurable range, or in the case of content determination simply in the range of 80-120% of the nominal value. 

Rapid chemical quench has been enormously powerful and helped to open the field of transient enzyme catalysis, as described above however, an alternative strategy is required for the detection and characterization of labile intermediates that avoids the need for chemical quenching. The coupling of rapid mixing techniques with online MS detection not only offers an option for the detection of labile intermediates but also has many general applications in the study of enzyme catalysis to more precisely define the key chemical events occurring at the active site. 

When naphthalene is degraded by permanganate under precisely defined conditions, phthalonic acid can be isolated instead of the usual phthalic acid, and this intermediate can be decarboxylated to phthalaldehydic acid (see page 1007) 150... 

Precision-. The USP defines precision as the degree of agreement among individual test results when the method is applied repeatedly to multiple samplings of a homogeneous sample. Precision may be measured as repeatability, reproducibility, and intermediate precision. 

Precision (ICH) The closeness of agreement (degree of scatter) between a series of measurements obtained from multiple sampling of the same homogenous sample under defined conditions. Precision is considered at three levels repeatability, intermediate precision, and reproducibility. In statistics, precision is typically reported as % coefficient of variation (% CV), also referred to as relative standard deviation (RSD). 

Precision is defined as the measure of how close the data values are to each other for a number of measurements under the same analytical conditions . Taken together with accuracy, precision indicates how close an analyst will be to 50 mg (see above) on repeated measurements. Precision includes three sub-sections repeatability, intermediate precision, and reproducibility. 

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