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Products & Services

We offer the only software packages and custom software for evaluation, measurement and decision making that are based on sound mathematical foundations. We also provide consulting services and training in the use of this software.

The Importance of Sound Mathematical Foundations

Without proper mathematical foundations, the numbers produced by competing products are meaningless. The problem of mathematical foundations is difficult and classical decision and measurement theories are founded on errors. Among other things, the elementary operations of addition and multiplication are not applicable to scale values that are constructed by any of these theories. For details see our Publications and Presentations pages.

Preference Function Modeling &

We have developed a new theory of proper measurement and, based on this theory, a new practical methodology named Preference Function Modeling (PFM).1 Tetra, our software implementation of PFM, has features unlike any competing product. In addition to its sound mathematical foundations, its user interface includes innovations that make it easy to learn. The multi-user version is the only available true Group Decision Making software with proper mathematical foundations.

PFM is a methodology for multi-criteria and multi-user evaluation, decision making and subjective measurement. It constructs a mathematical model (preference function) of the Decision Maker's preferences. PFM handles weights and relative importance correctly to enable Decision Makers to measure the performance of alternatives under conflicting criteria and it produces preference measurement scales that enable addition, multiplication, order and the application of calculus. Tetra is a faithful implementation of PFM.

For information on purchasing Tetra, or to download the free demo, please visit our Try & Buy page.

1 For details on PFM, see our Publications and Presentations pages.

NEW BOOK: Pure Economics On Neural Network Accuracy and Validation On Neural Network Mini-Batches On Neural Network Training Algorithms Spectrum and Optimization Algorithms ChoiceRobot

The Foundations

Decision Theory Utility Theory


Download Tetra Tetra Quickstart Guide Tetra Online Documentation


Numerical Mathematics


An Elementary Demand Theory Error Ordinal Utility and Indifference Curves Von Neumann's Error Game Theory: Whose Values?