Definition

ISO 3534-2:2006: value that serves as an agreed-upon reference for comparison, which is derived as:

a) a theoretical or established value, based on scientific principles;

b) an assigned or certified value, based on experimental work of some national or international organization;

c) a consensus or certified value, based on collaborative experimental work under the auspices of a scientific or engineering group;

d) the expectation, i.e. the mean of a specified population of measurements when a), b) and c) are not available.

Definition

ICH: The closeness of agreement between the value which is accepted either as a conventional true value or an accepted reference value and the value found.

MSA: "Closeness" to the true value, or to an accepted reference value.

Definition

Minitab: The predicted R-squared indicates how well a regression model predicts responses for new observations. This statistic helps you determine when the model fits the original data but is less capable of providing valid predictions for new observations.

Definition

ISO 3534: The alternative hypothesis is a statement which contradicts the null hypothesis. The corresponding test statistic is used to decide between the null and alternative hypothesis.

Definition

IATF 16949: A statistical method often used in designed experiments, to analyze variable data from multiple groups in order to compare means and analyze sources of variation.

Definition

IATF 16949 : Operator

Definition

MSA : Attribute measurement systems are the class of measurement systems where the measurement value is one of a finite number of categories. This is contrasted to the variables measurement system which can result in a continuum of values.

Definition

6 sigma: Use Attribute Gage Study (Analytic Method) to assess the amount of bias and repeatability in an attribute gage that gives a binary response, such as pass or fail.

Definition

ISO 3534: Arithmetic mean: sum of random variables in a random sample divided by the number of terms in the sum.

Definition

6 sigma: A hypothesis test used when analyzing the difference between the means obtained from two independent samples when the population's standard deviation is not known.

Definition

6 sigma: Type of hypothesis test that compares variances of two or more normally distributed populations.

Definition

6 sigma: Risk of concluding that two characteristics are the same when they are actually different.

Definition

ISO 3534-2:200: difference between the expectation of the test results and a true value

Note 1 to entry: Bias is the total systematic error as contrasted to random error. There can be one or more systematic error components contributing to the bias. A larger systematic difference from the accepted reference value is reflected by a larger bias value.

Note 2 to entry: The bias of a measuring instrument is normally estimated by averaging the error of indication over an appropriate number of repeated measurements. The error of indication is the ‘’indication of a measuring instrument minus a true value of corresponding input quantity’’.

Note 3 to entry: In practice, the accepted reference value is substituted for the true value.

Definition

Definition

IATF 16949: A specified amount of time or set of conditions between calibrations during which the calibration parameters of ameasuring device are considered valid.

Definition

IATF 16949: An estimate of the combined variation of measurement errors (random or systematic) based on a short-term assessment of the measurement system.

MSA: Capability indicies are used to predict the performance of a process by comparing the width of process variation to the width of the specified tolerance.

Definition

6 sigma: The Cause and Effect Diagram (C&E Diagram) is a fishbone-shaped diagram that helps a team brainstorm potential root causes of a defect. The problem to be solved is placed at the head of the fish and the six thought-generating categories - Personnel, Machines, Materials, Methods, Measurements and Environment - are placed at the ends of the fish bones.

Definition

Guide EURACHEM: Reference material, accompanied by a certificate, one or more of whose property values are certified by a procedure, which established its traceability to an accurate realisation of the unit in which the property values are expressed, and for which each certified value is accompanied by an uncertainty at a stated level of confidence.

Definition

Minitab : there are 2 common chi-squared tests : Pearson chi-square test and likelihood-ratio chi-square test. Each chi-square test can be used to determine whether or not the variables are associated (dependent).

The Pearson chi-square statistic (χ2) involves the squared difference between the observed and the expected frequencies.

The likelihood-ratio chi-square statistic (G2) is based on the ratio of the observed to the expected frequencies.

Definition

6 sigma: A measure of the correlation between the dependent and independent variables in a Regression Analysis.

Definition

MSA : fixed and defined conditions of measurement (instrument, standard, method, operator, environment, and assumptions)

Definition

ISO 3534-2:2006: observation conditions where independent test results are obtained with the same method on identical test or measurement items in different test or measurement facilities with different operators using different equipment

Definition

IATF 16949: The range of values expected to include ( at a some desired probability called a confidence level) the true value of a parameter.

6 sigma: A range of numbers in which population parameters are likely to fall

Definition

6 sigma: The fixed probability of correctly accepting the null hypothesis

Definition

MSA: The range of values expected to include (at some desired probability called a confidence level) the true value of a parameter.

Definition

MSA : Conformance is a conclusion given following a product control situation when a measurement result is compliant with a defined specification.

Definition

MSA: It is the difference in the variation of the measurements taken over time. It may be viewed as repeatability over time.

Definition

ISO 3534: Graphique sur lequel sont reportées les valeurs d'une mesure statistique faite sur une série d'échantillons dans un ordre particulier pour orienter le processus en fonction de cette mesure et pour contrôler et réduire la variation.

Definition

ISO 3534: Valeur utilisée pour déterminer la stabilité d'un processus.

Definition

It is a measure of the degree of linear relationship between two sets of data.The correlation coefficient ranges from -1 a perfect negative relationship, through 0 (no relationship), to +1, a perfect positive relationship.

Definition

ISO 3534: Sum of products of deviations of pairs of random variables in a sample from their sample means divided by the number of term in the sum minus one.

Definition

MSA: It is the ratio of the customer-specified tolerance to six standard deviations of the short-term process variation

6 sigma: A capability index that measures the potential capability of a process to meet expected specification limits, or tolerance levels, in the short term, assuming the process is ideally centered (regardless of where the process is actually centered).

Definition

MSA: It is a ratio of the distance between the process average and the closet specification limit, to three standarddeviations of the short-term process variation.

6 sigma: A capability index that measures the potential capability of a current process to meet expected specification limits, or tolerance levels, in the short term, using the current process average.

Definition

ISO 3534: Nombres de termes d'une somme moins le nombre de contraintes sur les termes de la somme.

Definition

Minitab : to summarize numeric data with a variety of statistics such as the sample size, mean, median, and standard deviation. 

Definition

ICH: It is the lowest amount of analyte in a sample which can be detected but not necessarily quantitated as an exact value.

Definition

6 sigma: The distance between a data point and the mean. Deviation measures and describes the variation in a set of data.

Definition

6 sigma: Numeric data that is not capable of being meaningfully subdivided into more precise increments.

Definition

6 sigma: A controlled variable, X, whose influence is being studied by varying it to different levels in a Design of Experiments (DOE).

Definition

Minitab: If the calculated F-value is greater than the F-value from the F-distribution, then at least one of the coefficients is not equal to zero. The F-value is used to determine the p-value.

Definition

MSA: Gage repeatability and reproducibility: the combined estimate of measurement system repeatability and reproducibility.

Definition

ISO 3534: Statement about a population.

Definition

Minitab: In general, a hypothesis test is a process in which you assume an initial claim to be true and then test this claim using sample data. Ordinarily, the initial claim refers to a population parameter of interest such as the population mean (ymean).

Definition

ICH: It expresses within-laboratories variations: different days different analysts, different equipment,etc.

Definition

6 sigma: Type of Test of Two Variances that compares variances of two or more populations that are not normally distributed.

Definition

ISO 3534-2:2006: r

repeatability critical difference for a specified probability of 95 %

Definition

ISO 3534-2:2006: R

reproducibility critical difference for a specified probability of 95 %

Definition

ICH: It is the ability (within a given range) to obtain test results which are directly proportional to the concentration (amount) of analyte in the sample.

MSA: The correlation multiple and independent bias errors over the operating range. A system error component of the measurement system. The difference of bias throughout the espected operating (measurement) range of the equipment.

Definition

6 sigma: The Lower Control Limit (LCL) is a limit in the Control Chart that is set below the centerline, typically at -3 standard deviations, in order to determine whether or not the process is in control.

Definition

6 sigma: A Lower Specification Limit (LSL) is the lower limit of a tolerance range specified by a customer requirement. A measured value that is below this limit is considered a defect

Definition

6 sigma: The complete process used to obtain measurements, including gages, operators, procedures and conditions.

Definition

A non-conformance (or 'nonconformity') means that something went wrong. The non-conformance could be in a service, a product, a process, goods from a supplier, or in the management system itself. It occurs when something does not meet the specifications or requirements in some way.

Definition

Minitab: If your data are perfectly normal, then the data points on the probability plot will form a straight line.

Definition

6 sigma: A distribution of data described by the mean and standard deviation. The curve displaying the distribution of data is shaped like a bell, with the area under the curve representing 100% of all possible observations.

Definition

6 sigma: A type of plot that represents normally distributed sample data.

Definition

n replicates are repeat measurements made at the same level.

Definition

ISO 3534: Obtained value of a property associated with one member of a sample

Definition

ISO 5725-2: value from a set of values which is inconsistent with the other values of that set, identified by a statistical test

Note 1 to entry: ISO 5725-2 specifies the statistical tests and the significance level to be used to identify outliers in trueness and precision experiments.

Definition

6 sigma: A sample in which each sampling unit contains a pair of observations that are not independent of one another (e.g. sampling ages of husband and wife as a single sampling unit).

Definition

6 sigma: A type of hypothesis test used when analyzing the difference between the means obtained from paired samples.

Definition

TS 16949: Piece-to-piece variation due to measuring different parts.

Definition

MSA: It is the net effect of all significant and determinable sources of variation over time. Performances quantifies the long term assessment of combined measurement errors.

Definition

ISO 3534: Totality of items under consideration.

Definition

ISO 3534: One minus the probability of the type II error.

Definition

6 sigma: A capability index that measures the potential capability of a process to meet expected specification limits, or tolerance levels, in the long term, assuming the process is ideally centered (regardless of where the process is actually centered).

Definition

6 sigma: A capability index that measures the potential capability of a current process to meet expected specification limits, or tolerance levels, in the long term, using the current process average.

Definition

ISO 3534-2:2006: : closeness of agreement between independent test results obtained under stipulated conditions

Note 1 to entry: Precision depends only on the distribution of random errors and does not relate to the true value or the specified value.

Note 2 to entry: The measure of precision is usually expressed in terms of imprecision and computed as a standard deviation of the test results. Less precision is reflected by a larger standard deviation.

Note 3 to entry: Quantitative measures of precision depend critically on the stipulated conditions. Repeatability and reproducibility conditions are particular sets of extreme conditions.

Definition

Minitab: Indicates how well the model predicts responses for new observations, whereas R2 indicates how well the model fits your data. Predicted R2 is between 0 and 1; larger values of predicted R2 suggest models of greater predictive ability.

Definition

Minitab: Prediction sum of squares; an assessment of your model's predictive ability. PRESS, similar to the residual sum of squares, is the sum of squares of the prediction error.

Definition

Minitab: The p-value is the probability of obtaining a test statistic that is at least as extreme as the actual calculated value, if the null hypothesis is true. A commonly used cut-off value for the p-value is 0.05.

Definition

ICH: It is the lowest amount of analyte in a sample which can be quantitativelydetermined with suitable precision and accuracy.

Definition

ISO 3534: Sample which has been selected by a method of a random selection.

Definition

ICH: It is the interval between the upper and lower concentration of analyte in the sample (including these concentrations), for which it has been demonstrated that the analytical procedure has a suitable level of precision, accuracy and linearity.

6 sigma: The difference between the largest and smallest observations in a data set.

Definition

Guide EURACHEM: The fraction of analyte added to a test sample (fortified or spiked sample) prior to analysis, the unfortified and fortified samples.

Definition

Guide EURACHEM: Material or substance one or more of whose property values are sufficiently homogeneous and well established to be used for the calibration of an apparatus, the assessment of a measurement methode, or for assigning values to materials.

Definition

MSA: Accepted value of an artifact, which requires an operational definition. Used as the surrogate for the true value.

Definition

This term is used to describe a group of method that summarize the degree of association between one variable (or set of variables) and another variables (or set of variables). The most common statistical method used to do this is the least squares regression, which works by finding the "best curve" through the data that mimizes the sums of square residuals.

Definition

MSA: A statistical study of the relationship between two or more variables. A calculation to define the mathematical relationship between two or more variables.

Definition

ICH: Repeatability expresses the precision under the same operating conditions over a short interval of time. It is also termed intra-assay precision.

MSA: Variation in measurements obtained with one measuring instrument when used several times by an appraiser while measuring a characteristic on the same part. The variation in successive (Short term) trials under fixed and defined conditions of measurement.

Definition

ISO 3534-2:2006: r

repeatability critical difference for a specified probability of 95 %

Definition

6 sigma: Repeated experimental trials that are made under identical factor levels and in similar conditions.

Definition

TS 16949: Multiple test trials under repeatability (identical) conditions.

Definition

ICH: It expresses the precision between laboratories (collaboratives studies, usually applied to standardization of methodology).

MSA: Variation in the average of the measurements made by different appraisers using the same gage when measuring a characteristic on one part.

Definition

Minitab: The difference between the observed values and predicted or fitted values (data minus fits). This part of the observation is not explained by the fitted model.

Definition

A residual value is calculated by taking the difference between the predicted value and the actual value. It can also be used to highlight points of influence (see bias, leverage and outliers).

Definition

Guide EURACHEM: Value attributed to a measurand, obtained by measurement.

Definition

ICH: It is a measure of its capacity to remain unaffected by small, but deliberate variations in method parameters and provides an indication of its reliability during normal usage.

Definition

Minitab: Coefficient of determination; indicates how much variation in the response is explained by the model. The higher the R2 , the better the model fits your data.

Definition

IATF 16949: A X-Y plot of data to assess the relationship between two variables.

Definition

MSA: Is the smallest input that results in detectable (useable) output signal. It is the responsivness of the measurement system to changes in measured feature.

Definition

ISO 3534: Procedure to decide if a null hypothesis is to be rejected in favour of an alternative hypothesis.

Definition

ISO 3534: Maximum probability of rejecting the null hypothesis when in fact it is true.

Definition

ICH: Garantie d'évaluer une substance en présence d'autres composés (impuretés,produits de dégradation, matrice…).

Definition

Minitab : The standard deviation is most common measure of dispersion, or how spread out the data are from the mean. The greater the standard deviation, the greater the spread in the data. The symbol σ (sigma) is often used to represent the standard deviation of a population, while s is used to represent the standard deviation of a sample

Definition

6 sigma: Standard Operating Procedure (SOP) is an organized way of disseminating information, regarding actions, responsibilities and preventive measures associated with process variables. SOP's ensure a predictable output and reduce the chances for unintended variation

Definition

Minitab: The sum of squared distances. SS Total is the total variation in the data. SS Regression is the portion of the variation explained by the model, while SS Error is the portion not explained by the model and is attributed to error. SS Total= SS Regression + SS Error

Definition

MSA: Short term estimate of measurement system variation.

Definition

6 sigma: The difference between the Upper Specification Limit (USL) and the Lower Specification Limit (LSL).

Definition

closeness of agreement between the expectation of test results and a true value

Note 1 to entry: The measure of trueness is usually expressed in terms of bias.

Note 2 to entry: Trueness is sometimes referred to as “accuracy of the mean”. This usage is not recommended.

Note 3 to entry: In practice, the accepted reference value is substituted for the true value.

Definition

MSA: Actual value of an artifact

Definition

Minitab: Compare the t-value to the t-distribution to determine if a predictor is significant. The bigger the absolute value of the t-value, the more likely the predictor is significant.

Definition

GUM/VIM: Paramètre, associé au résultat d'un mesurage, qui caractérise la dispersion des valeurs qui pourraient raisonnablement être attribuées au mesurande.

Definition

6 sigma: The Upper Control Limit (UCL) is a limit in the Control Chart, set above the centerline, typically at +3 standard deviations, in order to determine if the process is in or out of control.

Definition

6 sigma: The Upper Specification Limit (LSL) is the upper limit of a tolerance range specified by a customer requirement. A measured value that is above this limit is considered a defect.

Definition

ICH: The analytical procedure refers to the way of performing the analysis. It should describe in detail the steps necessary to perform each analytical test.

Definition

ISO 3534: Somme des carrés des écarts des valeurs d'un échantillon à sa valeur moyenne, divisée par le nombre de termes de la somme moins 1.

Definition

Weighted regression works by giving points known to have a better precision a higher weighting than those with lower precision

Definition

6 sigma: A type of Control Chart that plots the subgroup means and the subgroup ranges.