Evidence has shown that the use of restricted natural
languages can reduce ambiguities in textual use case specifications
(UCSs). Restricted natural languages often come with specific
editors that support particular use case templates and provide
enforcement of the language?s restrictions. However, whether
restriction enforcement facilitates the definition of UCSs as
compared to an editor without such support is a fundamental
question to answer. To this end, we report results of a controlled
experiment in which we compared two approaches for defining
restricted UCSs: (i) a specific Restricted Use Case Modeling
(RUCM) tool that supports restriction enforcement; and (ii) a
general Office Word UCS template without such enforcement. We
compared both approaches from multiple perspectives including
restriction misuse, understandability, and restrictiveness. Results
show that the restriction misuse rates are generally low, which
indicates the usefulness of the RUCM, independent of the use of
the editors. The results also indicate that the RUCM tool eases
the application of more complex restrictions. We also found that
the participants profited from extensive training prior to the
experiment. The experiment participants further showed their
strong willingness to recommend the RUCM tool to others and
to use it in the future, which was not the case for the Office
Word template.
Index Terms?Use case modeling, restricted natural language,
controlled experiment.