The identification and specification of the requirements of a software system is a difficult task that has the goal of obtaining requirements as correct and complete as possible.It is extremely important that Requirements Engineers understand a domain language in order to write high-quality requirements.Moreover, they must describe (and discuss) the language in a collaborative way in order to consider the different points of view of all stakeholders to assure that the resulting requirements will have more chances to meet their needs.However, collaborative construction implies the occurrence of conflicts that are unavoidable because of ambiguity, overlapping and misunderstanding natural language descriptions.This article relies on the Language Extended Lexicon in order to describe the application domain.Although it is a semi-structured glossary and this characteristic helps to reduce the conflicts, our experience shows that conflicts arise anyway.Thus, in order to mitigate this problem, this article presents a catalogue with a set of conflicts that could appear during a collaborative construction of the Language Extended Lexicon and proposes alternatives for their resolution.

Estimating the size of a software system is a critical task due to the implications the estimation has in the management of the development project. There are some widely accepted estimation techniques: Function Points, Use Case Points and Cosmic Points, but these techniques can only be applied after the availability of a requirements specification. In this paper, we propose an approach to estimate the size of an application previous to its requirements specification by using the application language itself, captured by the Language Extended Lexicon (LEL). Our approach is based on Use Case Points and on a technique which derives Use Cases from the LEL. The proposed approach provides a measure of the application's size earlier than the usual techniques, thus reducing the effort needed to apply them. An initial experiment was conducted to evaluate the proposal.