# Tag Archives: model theory

## 1 + x = 3 as a Query

Strongly reduced recap of basic software engineering concepts: Query, Result Set, Requirement. Continue reading

## Reflections on Abstractions: The Use Case trade-off

Based on the elementary terms of relational structures, this little example shows the basic trade-off of Use Cases: understandability vs redundancy. Continue reading

## Examples of Preterition and Abundance in Modelling

In addition to the earlier posting “Stachowiak on Preterition and Abundance in Modelling” here are some examples of Preterition and Abundance in Photography, Use Case Models, and Graph or Flow notations. Continue reading

## Stachowiak on Preterition and Abundance in Modelling

In his 1973 book “Allgemeine Modelltheorie” Herbert Stachowiak discusses the concepts of Preterition, Abundance and Contrastation of Original-Model mappings. This can be interpreted using homomorphism preservation and other logical concepts. Continue reading

## Reflections on Abstractions: Correctness and Completeness

An earlier post on quality properties of models is compared to basic concepts of mathematical logic, in strive for rigour. What does a formal system of mathematical logic has in common with a modelling situation as in requirements analysis? It depends … Continue reading

## Models: Correct, Complete, Consistent, Unambiguous

How do you judge how ‘good’ or ‘bad’ a model is? I mean models like we use them in software requirements specification or business analysis. On this, one can find criteria in literature like BABOK, Wikipedia, IEEE, research papers, or textbooks. However, for some reason these criteria sets are quite different in each case. I’ve tried to get the things a little straighter, starting with the ‘big four’ quality characteristics of software requirements specifications … Continue reading

## Reflections on Abstractions: Cases vs Models

We describe by simple means of basic Finite Model Theory a very important principle in software engineering: modelling properties is more expressive than just collecting cases. This, for example, is the reason why test cases can be derived from specifications but not vice versa. Continue reading

## Stachowiak’s K-System of Modelling

Beyond the colloquial fundamental model properties Stachowiak gives a more formal definition of model: “Explication of the Concept of Model” … Continue reading

## General Model Theory by Stachowiak

In his 1973 book “Allgemeine Modelltheorie” (General Model Theory) Herbert Stachowiak describes the fundamental properties that make a Model: Mapping, Reduction, and Pragmatism. Continue reading

## Lazy Friday (and First Order Logic)

Can “the company has 3 problems” be formalized in First Order language? Picture the sentence in the context of a management presentation … Continue reading