Ambiguity defects as variation points in requirements

Software requirements are generally expressed in Natural Language. NL is intrinsically ambiguous, and this is seen as a possible source of problems in the later interpretation of requirements. However, ambiguity or under-specification at requirements level can in some cases give an indication of possible variability, either in design choice, in implemen- tation choices or configurability. Taking into account the results of previous analyses conducted on different require- ments documents with NL analysis tools, we attempt a first classification of the forms of ambiguity that indicate varia- tion points, and we indicate an approach to achieve auto- mated support to variability elicitation.