Use case templates can be used to describe functional requirements of a Software Product Line. However, to the best of our knowledge, no efforts have been made to collect and summarize these existing templates and no empirical evaluation of the use cases' comprehensibility provided by these templates has been addressed yet. The contributions of this paper are twofold. First, we present a systematic mapping study about the SPL variability description using textual use cases. From this mapping,

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... found twelve SPL use case templates and observed the need not only for the application of these templates in real SPL but also for supporting tools. Secondly, this work presents an evaluation of the comprehensibility of SPL use cases specified in these templates through a controlled experiment with 48 volunteers. The results of this experiment show that the specification of variabilities in the steps' numeric identifiers of the textual use cases is better to the use case understanding than the other approaches identified. We also found evidence that the specification of variabilities at the end of the use cases favors the comprehension of them and the use of questions associated to the variation points in the use cases improves the understanding of use cases. We conclude that each characteristic of the existing templates has an impact on the SPL use case understanding and this should be taken into account when choosing one.