Abstract
A long stream of research in RE has been devoted to analyzing the occurrences and consequences of ambiguity in requirements documents. Ambiguity often occurs in documents, most often in natural language (NL) ones, but occasionally also in formal specifications, be it because of abstraction, or of imprecise designation of which real-world entities are denotated by certain expressions. In many of those studies, ambiguity has been considered a defect to be avoided. In this paper, we investigate the nature of ambiguity, and advocate that the simplistic view of ambiguity as merely a defect in the document does not do justice to the complexity of this phenomenon. We offer a more extensive analysis, based on the multiple linguistic sources of ambiguity, and present a list of real-world cases, both in written matter and in oral interviews, that we analyze based on our framework. We hope that a better understanding of the phenomenon can help in the analysis of practical experiences and in the design of more effective methods to detect, mark and handle ambiguity.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Notes
- 1.
In fact, a statement can be ambiguous or not depending on which particular semantics we observe. For example, a requirement asking for a given feature in ambiguous terms could be interpreted in several different ways for the purpose of implementing the feature, and thus be ambiguous; however, if the possible interpretations all have the same implementation costs, the meaning would be unique for cost-estimate purposes, and thus no ambiguity would arise in that particular denotation.
- 2.
The Bahá’í calendar, for example, has 19 months of 19 days each, plus 4 intercalary days (5 in leap years) which are not part of any month. How would our requirement be interpreted in a Bahá’í community?
- 3.
For a concrete example, even an experienced C language programmer might look puzzled at a statement like long c=3["test"]; which is perfectly legal and unambiguous in the language. But then, int x=*(char *)&c;, which is again legal, produces results which are not specified by the semantics, and is thus ambiguous (probably, x would be either 0 or 116).
- 4.
- 5.
Ergative is the grammatical case for nouns that identify the intentional agent of a verb (especially a transitive verb), often marked by a special suffix or prefix.
- 6.
The reader will notice that the ambiguity is not raised by the vague expression a lot, which appeared acceptable at that stage of the conversation.
- 7.
A deictic expression refers to something that only exist in the context, e.g. “here” referring to the current location of the speaker, never appearing in text.
- 8.
- 9.
- 10.
References
Zowghi, D., Gervasi, V.: The 3Cs of requirements: consistency, completeness, and correctness. In: Salinesi, C., Regnell, B., Pohl, K. (eds.) Proceedings of REFSQ 2002, Essener Informatik Beitrage, pp. 155–164, September 2002
Zowghi, D., Gervasi, V.: On the interplay between consistency, completeness, and correctness in requirements evolution. Inf. Softw. Technol. 46(11), 763–779 (2004)
Gervasi, V., Zowghi, D.: On the role of ambiguity in RE. In: Wieringa, R., Persson, A. (eds.) REFSQ 2010. LNCS, vol. 6182, pp. 248–254. Springer, Heidelberg (2010). https://doi.org/10.1007/978-3-642-14192-8_22
Scott, D., Strachey, C.: Toward a mathematical semantics for computer languages. Technical report PRG-6, Oxford Programming Research Group (1971)
ISO: Information Technology - Z Formal Specification Notation - Syntax, Type System and Semantics. ISO (2002)
Scott, D.S.: Lambda calculus: some models, some philosophy. In: Barwise, J., Keisler, H.J., Kunen, K. (eds.) The Kleene Symposium, pp. 223–265. North-Holland Publishing Company, Amsterdam (1980)
Fabbrini, F., Fusani, M., Gervasi, V., Gnesi, S., Ruggieri, S.: On linguistic quality of natural language requirements. In: Dubois, E., Opdahl, A.L., Pohl, K. (eds.) Proceedings of REFSQ 1998, 57–62. Presses Universitaires de Namur, Pisa (1998)
Berry, D., Kamsties, E., Krieger, M.: From contract drafting to system specification: linguistic sources of ambiguity (2003)
Berry, D., Bucchiarone, A., Gnesi, S., Lami, G., Trentanni, G.: A new quality model for natural language requirements specifications. In: Proceedings of REFSQ 2006, Luxembourg (2006)
Kiyavitskaya, N., Zeni, N., Mich, L., Berry, D.M.: Requirements for tools for ambiguity identification and measurement in natural language requirements specifications. Requir. Eng. 13(3), 207–239 (2008)
Jackson, M.: Problem Frames. Addison Wesley, Harlow (2001)
Fellbaum, C. (ed.): WordNet: An Electronic Lexical Database. MIT Press, Cambridge (1998)
Breitman, K.K., Sampaio do Prado Leite, J.C.: Lexicon based ontology construction. In: Lucena, C., Garcia, A., Romanovsky, A., Castro, J., Alencar, P.S.C. (eds.) SELMAS 2003. LNCS, vol. 2940, pp. 19–34. Springer, Heidelberg (2004). https://doi.org/10.1007/978-3-540-24625-1_2
Plato: Cratylus. In: Cooper, J.M., Hutchinson, D.S. (eds.) Plato Complete Works. Hackett Publishing (1997)
Carroll, L.: Through the Looking-Glass, and What Alice Found There. Macmillan, London (1871). (pseudonym of C. L. Dodgson)
Rice, S.L.: Loglan 3: Understanding Loglan. Master’s thesis, University of Alaska at Fairbanks, May 1994. (Reprinted in serialized form by the Loglan Institute, Inc. in La Logli issues 1997/1, 1997/2 and 1997/3)
Berry, D.M., Kamsties, E.: Ambiguity in requirements specifications. In: do Prado Leite, J.C.S., Doorn, J.H. (eds.) Perspectives on Software Requirements, vol. 753, pp. 7–44. The Kluwer International Series in Engineering and Computer Science. Springer (2004)
Gervasi, V.: Environment Support for Requirements Writing and Analysis. Ph.D. thesis, University of Pisa, March 2000
Chung, L., Nixon, B., Yu, E., Mylopoulos, J.: Non-functional Requirements in Software Engineering. Kluwer Academic Publishers, Massachusetts (2000)
Peano, G.: Arithmetices principia, nova methodo exposita. Fratres Bocca, Turin (1889). (in Latin)
Meyer, B.: On formalism in specifications. IEEE Softw. 2(1), 6–26 (1985)
Ferrari, A., et al.: Detecting requirements defects with NLP patterns: an industrial experience in the railway domain. Empirical Softw. Eng. 23(6), 3684–3733 (2018)
Yang, H., Deroeck, A., Gervasi, V., Willis, A., Nuseibeh, B.: Extending nocuous ambiguity analysis for anaphora in natural language requirements. In: Proceedings of the 18th IEEE International Requirements Engineering Conference, Sydney (2010)
Chantree, F., Nuseibeh, B., de Roeck, A., Willis, A.: Identifying nocuous ambiguities in requirements specifications. In: Proceedings of 14th IEEE International Requirements Engineering Conference (RE 2006), Minneapolis/St. Paul, Minnesota, September 2006
Ferrari, A., Spoletini, P., Gnesi, S.: Ambiguity and tacit knowledge in requirements elicitation interviews. Requirements Eng. 21(3), 333–355 (2016)
Ferrari, A., Spoletini, P., Gnesi, S.: Ambiguity cues in requirements elicitation interviews. In: IEEE 24th International Requirements Engineering Conference (RE), pp. 56–65. IEEE (2016)
Boehm, B.: Some experiences with automated aids to the design of largescale reliable software. IEEE Trans. Software Eng. 1(1), 125–133 (1975)
Gause, D.C., Weinberg, G.M.: Exploring Requirements: Quality Before Design. Dorset House, New York (1989)
Schneider, G.M., Martin, J., Tsai, W.T.: An experimental study of fault detection in user requirements documents. ACM Trans. Softw. Eng. Methodol. 1(2), 188–204 (1992)
Kovitz, B.: Ambiguity and what to do about it. In: Proceedings of the 10th International Conference on Requirements Engineering. IEEE Computer Science Press, Los Alamitos (2002)
Fabbrini, F., Fusani, M., Gnesi, S., Lami, G.: An automatic quality evaluation for natural language requirements. In: Proceedings of REFSQ 2001, Interlaken (2001)
Gnesi, S., Lami, G., Trentanni, G., Fabbrini, F., Fusani, M., et al.: An automatic tool for the analysis of natural language requirements. Int. J. Comput. Syst. Sci. Eng. 20(1), 53–62 (2005)
Bubka, A., Gorfein, D.S.: Resolving semantic ambiguity: an introduction. In: Gorfein, D.S. (ed.) Resolving Semantic Ambiguity, pp. 3–12. Springer, New York (1989). https://doi.org/10.1007/978-1-4612-3596-5_1
Kamsties, E., Berry, D., Paech, B.: Detecting ambiguities in requirements documents using inspections. In: Workshop on Inspections in Software Engineering (WISE 2001), Paris, pp. 68–80 (2001)
Gleich, B., Creighton, O., Kof, L.: Ambiguity detection: towards a tool explaining ambiguity sources. In: Wieringa, R., Persson, A. (eds.) REFSQ 2010. LNCS, vol. 6182, pp. 218–232. Springer, Heidelberg (2010). https://doi.org/10.1007/978-3-642-14192-8_20
Tjong, S.F., Berry, D.M.: The design of SREE — a prototype potential ambiguity finder for requirements specifications and lessons learned. In: Doerr, J., Opdahl, A.L. (eds.) REFSQ 2013. LNCS, vol. 7830, pp. 80–95. Springer, Heidelberg (2013). https://doi.org/10.1007/978-3-642-37422-7_6
Ferrari, A., Dell’Orletta, F., Esuli, A., Gervasi, V., Gnesi, S.: Natural language requirements processing: a 4D vision. IEEE Softw. 34(6), 28–35 (2017)
Femmer, H., Fernández, D.M., Wagner, S., Eder, S.: Rapid quality assurance with requirements smells. J. Syst. Softw. 123, 190–213 (2017)
Ferrari, A., Spoletini, P., Gnesi, S.: Ambiguity as a resource to disclose tacit knowledge. In: Zowghi, D., Gervasi, V., Amyot, D. (eds.) 23rd IEEE International Requirements Engineering Conference, RE 2015, Ottawa, 24–28 August 2015, pp. 26–35. IEEE Computer Society (2015)
Merlini Barbaresi, L.: Markedness in English Discourse: A semiotic approach. Edizioni Zara, Parma (1988)
Chandler, D.: Semiotics: The Basics, 2nd edn. Routledge, London (2007)
Acknowledgment
The authors would like to thank Stefania Gnesi for her pioneering work on ambiguity in requirements documents, and for the many scientific collaborations with her, on several subjects, that they have enormously enjoyed along the years. The first author wishes to acknowledge the financial support of the Centre for Human-Centred Technology Design Research at UTS which partially sponsored the present work. This work was partially supported by the National Science Foundation under grant CCF-1718377.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2019 Springer Nature Switzerland AG
About this chapter
Cite this chapter
Gervasi, V., Ferrari, A., Zowghi, D., Spoletini, P. (2019). Ambiguity in Requirements Engineering: Towards a Unifying Framework. In: ter Beek, M., Fantechi, A., Semini, L. (eds) From Software Engineering to Formal Methods and Tools, and Back. Lecture Notes in Computer Science(), vol 11865. Springer, Cham. https://doi.org/10.1007/978-3-030-30985-5_12
Download citation
DOI: https://doi.org/10.1007/978-3-030-30985-5_12
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-030-30984-8
Online ISBN: 978-3-030-30985-5
eBook Packages: Computer ScienceComputer Science (R0)