All calculations are performed using double-precision IEEE 754 standard, highly reliable numerical methods, and then tested rigorously.
To ensure that Analyse-it produces accurate results it does not use any Excel mathematical, statistical or distribution functions. Many of these functions in early versions of Microsoft Excel used poor algorithms that often produced inaccurate results. Functions like STDEV and LINEST were affected, as were add-ins that used those functions. Microsoft has now addressed most of the problems, though you may still hear warnings against using Microsoft Excel for statistical analysis.
To avoid any of these problems Analyse-it uses reliable numerical algorithms and all calculations are performed using double-precision (IEEE 754 standard, effectively 15 significant digits). We then verify the statistics are correct, and remain so, throughout the development and release process using an in-house library of thousands of validation unit-tests.
