Streamlined and prioritized hierarchical relations : a technique for improving the effectiveness of the classification-tree methodology
Abstract of thesis entitled
Streamlined and Prioritized Hierarchical Relations ?a Technique for Improving the Effectiveness of the Classification-Tree Methodology
Wing Hong Kwok
for the degree of Master of Philosophy
at The University of Hong Kong
in August 2001
The effectiveness of test case generation from a classification tree associated with a software specification is the topic studied and reported in this thesis. Among the techniques for determining test cases from a classification tree, the Classification-Tree Methodology (CTM) has been selected for investigation. Through the study of CTM with real-life applications, we have identified a number of areas for improving the effectiveness on the construction of classification trees.
The original CTM introduced the concept of a classification-hierarchy table as a tool to tabulate the relations among classifications for constructing a classification tree. With n classifications being identified from a specification, where n > 2, there would be n2 relations to be determined in order to complete the table. By taking an iterative approach for identifying classifications, we conduct the relation determination process only when necessary, instead applying it to all classifications. This new identification approach thus reduces the number of the relations to be determined.
For precisely describing the class coexistence between two classifications, we have refined the so-called other relations in CTM into two new types: full class coexistence and partial class coexistence. Recognizing the significance of the full class coexistence relations in the construction of a classification tree, we have enhanced the tree construction technique in CTM to resolve the problems observed from the study.
The original CTM constructed a classification tree by merging only classifications with ancestor-descendant relations in a classification-hierarchy table. A classification tree with multiple top-level classifications could result. With the concept of
single top-level classification for building a classification tree in a top-down manner, while the classification tree is being constructed, we can eliminate the invalid class combinations caused by joining different classes of identical classifications due to multiple top-level classifications or classes from distinct classifications.
We prioritize the relations in a classification-hierarchy table for manipulating classifications such that a classification tree constructed under the priority scheme can generate all legitimate test cases associated with the classification-hierarchy table. Because of the manipulation approach integrating the hierarchy revision of a classification tree and the examination of the validity of class combinations in a single process for generating test cases, all test cases generated by this new construction approach are legitimate.
School:The University of Hong Kong
School Location:China - Hong Kong SAR
Source Type:Master's Thesis
Keywords:computer software testing reliability trees graph theory
Date of Publication:01/01/2003