Note: This page now accepts data where either a comma (,) or point (.) is used as the decimal separator.
This utility evaluates the repeatability of a test, based on the results
of repeated testing on a series of 1 or more samples for a test
producing a continuous outcome.
Data required is a series of test results for a panel of one or more samples.
The first row of the data is expected to contain column headers identifying each of the sample series.
The first column is assumed to contain identifiers for each test occasion
(for example plate numbers, dates or just a sequential number). Testing data is
assumed to be temporally ordered and matched across samples.
Additional columns (after the first) are assumed to contain test results for the
samples to be evaluated.
Outputs include (for each sample):
- Numerical and graphical summaries of testing results;
- Calculation of warning and critical limits and of numbers
and percentages of occasions when these limits are exceeded;
- Time series analysis, including plots of raw data, moving
average and lowess trend line;
- Summary of regression analysis for univariate linear trend; and
- Autocorrelation plot.
The width of the window for calculating moving averages can be set by the user.
Warning and critical limits can be either:
- Calculated from the data (mean +/- 2 and 3 standard deviations); or
- Calculated from mean and standard deviation values specified by the user
(mean +/- 2 and 3 standard deviations); or
- Specified explicitly by the user.