I made software testing my research area in the late 1980s, and have been actively involved in the following areas:
Unit Test Frameworks
My MSc project (circa 1991) was the development of an automatic generator of unit test frameworks for Ada. This concept has since been taken up commercially by testing tools suppliers and is now widely used in the form of xUnit test frameworks.
Test Effectiveness
From 1993 I performed research on the effectiveness of software testing techniques. This work was originally based on an operational avionics system and contributed a large part of my PhD thesis, submitted in 1997. The research was also used to validate the definitions of the test techniques in BS 7925-2 (see here for more on Standards).
One of my conference papers on test effectiveness is available for download here: 
Test Effectiveness Paper
PTMM – Personal Test Maturity Matrix
This framework was initially developed jointly with Julian Harty in 2005. Its original purpose was to provide guidance for software test practitioners who want to develop their skills. The PTMM comprises roles and skills, which are categorized into four main areas: test skills, IT skills, soft skills and domain knowledge. Thus, it is not simply about categorizing testing skills – it assumes that professional testers also need a range of other skills. An important point to note is that the framework assumes individual testers will decide on their own current capabilities – and where they want to go next. The PTMM is not prescriptive, it only provides a framework of roles and skills.
The PTMM framework describes the different roles that software testers take and the skills required to perform these roles. Individual testers initially identify their own specific skillspace, which describes their capabilities in each of the four main areas. They then use the PTMM to provide them with suggestions on which skills they might wish to improve or to acquire next.
Despite the PTMM initially being targeted at individuals, organizations providing testing services are also using the PTMM to define the provided (and required) skills of their staff.
One of my conference papers on PTMM is available for download here: PTMM paper
Tester Motivation
In 2011 I began research on what motivates testers with Tafline Ramos, largely based on a series of surveys of over 700 testers from around the world.
In the past the ‘common sense’ approach of rewarding good performance and punishing unwanted behaviour has been assumed to be the most effective motivator. Unhappily many of today’s managers still believe that this approach works, despite about 50 years’ of research showing otherwise. In fact, many of today’s motivation experts tell us that bonuses often do more harm than good. In practice, we now know that promising bonuses for creative work, such as test case design, actually slows their creation rather than enhancing it.
This research provides evidence-based data that provides insight into how we can both improve our own jobs and create motivating jobs for those we manage.
Conference papers and articles on Tester Motivation are available for download here:
- Motivated or Motivating – Tester Motivation
- Motivating Testers – What’s in a Role
- Tester Motivation Top Ten Tips
Artificial Intelligence and Autonomous Systems
In 2016 I started working more in the area of the testing of automotive systems and this led to research into self-driving cars and autonomous systems. The following responsibilities reflect this research area:
- 2018-Present Leader ISO Autonomous Systems Project
- 2017-Present Member SCSC Safety of Autonomous Systems WG
- 2017-2018 Leader ISO SC7 Autonomous Systems Study Group
As artificial intelligence is an integral part of most autonomous systems, I have subsequently taken a specific interest in the testing of artificial intelligence, resulting in the following roles:
- 2018-Present Project Editor ISO/IEC/IEEE 29119-11 TR: Testing of AI-Based Systems
- 2018-Present Editor KSTQB/CSTQB TAI Syllabus (and corresponding course)
The work in this area has been carried out with my colleague, Prof Qin Liu of Tongji University in Shanghai. The latest version of the syllabus for the certification course on the Testing of AI-Based Systems (62 pages) is available for download here:
