This stable version of the Guideline Wiki Page displays the guideline as per the i* Style of the University of Toronto. Registered users can use 'Open Version' link right at the end of the guideline statement below to access the open version of this page
Guideline (Beginner,Concept) Avoid introducing ad hoc or improvised link types. If you must, define their syntax and semantics as extensions to i*. Open Version
Discussion: Usually, Contribution Links are used to evaluate the satisfaction of Softgoals. In some instances, however, quantitative Contribution links labels (such as numbers or different symbolic types) can be used if real-life data or sources of numbers are available to evaluate contributions of alternative Tasks on the satisfaction of Softgoals. Otherwise, adding numbers is just making a finer-grained qualitative evaluation measure. The user of the model or the modeler has to be aware that it is still a qualitative measure, not to be totally trusted. Additionally, should the modeler need to introduce new link types, their syntax and semantics must be defined.
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