Results of an inter-laboratory proficiency test in XLSTAT
How to get data analysis on excel lab update#
It is also possible to update the robust estimate s* (scale) at each iteration of the algorithm. If the median absolute deviation (MAD) is zero, then you may replace it with the median of the absolute differences with the mean. The choice of the algorithm is usually taken by the proficiency testing provider and depends on various factors such as the number of participants and the amount of outliers in the measurements. For the algorithm A, you have the option to use the range, the standard deviation using the Grubbs approach to remove outliers, the nIQR, Qn or Q as the scale statistic. Select the scale statistic (range or the standard deviation) to be estimated by the robust using the algorithm S. If you want XLSTAT to exclude the errors in the computation of the Qn statistic (read our article for more details), deactivate the ISO-13528-2015 errors option. In the Options tab, choose whether you want to use the mean or the median as the location statistic. In the General tab, select the measuring results collected for each item (laboratories in this case) and choose the Item/Tests table format as rows correspond to laboratories and columns to measurements. The inter-laboratory proficiency testing dialog box appears. Once XLSTAT is open, select the XLSTAT / Laboratory data analysis / Inter-laboratory proficiency testing feature. Setting up an inter-laboratory proficiency test in XLSTAT Source: Statistical methods for use in proficiency testing by interlaboratory comparison. Rows represent the laboratories and columns the concentrations of antibodies for two allergens. The data are numbers of units in thousands per litre of sample, where a unit is defined by the concentration of an international reference material. The data provides the results obtained by testing two similar proficiency test items for antibody concentrations. As some errors have been detected in the 2015 version of the document (see here for further details), XLSTAT gives you the possibility to run the analysis with or without the errors. It was first developed using the 2015 edition. This tool is based on the ISO-13528 standard. It is useful to interpret the results and define to what extent the proficiency standards are met.
How to get data analysis on excel lab series#
XLSTAT allows for a highly automated analysis of the laboratory data and can yield a series of general and robust statistics. This process aims at evaluating and monitoring laboratories’ performance and is an essential part of quality assurance activities for testing laboratories. Proficiency Testing, also called interlaboratory comparison, compares the measurements made by several laboratories. What is inter-laboratory proficiency testing? This tutorial will help you set up and interpret an inter-laboratory proficiency test in Excel using the XLSTAT software.