This research arises out of projects to create systems to facilitate management of design and cost related knowledge within aerospace organisations, with the aim of using this knowledge to reduce the costs of designing and manufacturing products. This paper identifies ways that problems arising from the model development process can be addressed, by a new way of providing for the creation of software. We have gained experience from projects, which have used a combination of proprietary software solutions and bespoke software. It is possible to identify the approach of User Driven Programming (UDP) as an effective software development technique. This research unites approaches of Object Orientation, the Semantic Web, and Relational Databases and Event Driven programming. The approach encourages much greater user involvement in software development. The advantages of increasing user involvement in software development are explained by Olsson [1]. The intention of this research is to allow users to create the whole model/program they develop without typing code.
User Driven Programming (UDP) and User Driven Modelling (UDM) are techniques of End-User Programming, http://www.cs.cmu.edu/~bam/papers/EUPchi2006overviewColor.pdf explains End User Programming. A diagram from this presentation illustrates how small a proportion of development is carried out by professional developers.
Categories of User
It is important to distinguish between the two different types of users for the system, as they would work on different parts of the overall system. However a person may be represented in either or both categories.
Model Builders
Model builders create or edit the semantic representation of the model in an ontology editor in order to create models. Model builders do not need knowledge of a programming language, but do need training in how to use the ontology interface to create a model, and some knowledge of the domain to which it is to be applied.
Model Users
Model users make decisions based on their domain knowledge. This type of user manipulates the tree representation to obtain a result based on the input values they know, or otherwise based on default values. They will want to be able to use a model to evaluate a problem in order to help in decision making.
Expertise of Users
Within this paper the terms user, and domain expert are used interchangeably. The user is a domain expert who wants a problem represented and modelled using software. The domain is engineering but our research could be applied to other domains. The users/domain experts may well be computer literate and able to model certain problems using a software tool such as a spreadsheet. For reasons that will be explained later, this is only sufficient for simpler problems. The reasons that spreadsheets should not be used to represent complex models are connected with difficulties in maintaining, extending, and reusing spreadsheet models. This might not be such a problem in future if research such as that of Oregon State and Houston Universities can succeed in automatically generating correct spreadsheets, and solving errors of meaning (semantic errors) [2].
For now, to be able to model a complex problem, the users/domain experts currently must specify their requirements to other software experts, who may or may not have domain knowledge themselves. It is difficult to find and afford those who have sufficient expertise in both the software and the domain. Someone without the domain knowledge may not understand the requirements. Putting the right team together is a difficult balancing act, and sometimes may be difficult or impossible.
Software development is time consuming and error prone because of the need to learn computer languages. If people could instruct a computer without this requirement they could concentrate all their effort on the problem to be solved. This is termed User Driven Programming (UDP) within this paper, and for the examples demonstrated the term User Driven Modelling (UDM) is used to explain the application of User Driven Programming to model development. This research aims to create software that enables people to program using visual metaphors. Users enter information in a diagram, which for these examples is tree based. Tree based visualisation is often a good way of representing information structures and/or program code structures. The software developed as part of this research translates this human readable representation into computer languages. The tree also shows the flow of information. This technique is a kind of End User Programming, research in this area is undertaken by the EUSES (End Users Shaping Effective Software) research collaboration [3].
Our research is explained with examples at www.cems.uwe.ac.uk/~phale/.
References
1 Olsson, E. (2004). What active users and designers contribute in the design process, Interacting with Computers, 16: 377-401.
2 Stanford University. (2006). Stanford University - Welcome to protégé, protege.stanford.edu/.
3 EUSES. (2006). End Users Shaping Effective
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