  Stakeholders quantification plays a basic role in selecting the appropriate
requirements because their judgement is a major criteria since not all of them
have the same importance. Original proposals quantified stakeholders assigning
them a weight. Nonetheless, actual projects manage a numerous stakeholders
community hindering the inclusion of all their weights. This work proposes
grouping strategies as means to reduce the number of stakeholders to manage in
requirements selection keeping a proper coverage (i.e. howthe selection fulfils
stakeholder demands). Our approach is based on stakeholders' salience, defined
in terms of power, legitimacy and urgency attributes. Diverse strategies are
applied selecting important stakeholders groups in a specific project. We use
k-means}, k-medoids and hierarchical clustering, after deciding the number of
cluster (4 and 3) based on validation indices. Either for all the stakeholders
and each important group several requirements selection optimization problems
have been solved. Tests find no significant differences for coverage when
important stakeholders are filtered using clustering, regardless of the
technique and number of groups, with a reduction between 66.32% to 87.75% in
the number of stakeholders being considered. Applying clustering methods on
data obtained from a real-world project is useful to identify the group of
important stakeholders. The number of groups suggested matches the stakeholders
theory and the coverage values in the requirements selection is kept.
