On the effectiveness of screen mockups in requirements engineering: results from an internal replication

In this paper, we present and discuss the results of an internal replication of a controlled experiment for assessing the effectiveness of including screen mockups when adopting Use Cases. The results of the original experiment indicate a clear improvement in terms of understandability of functional requirements when screen mockups are present with no significant impact on effort. The data analysis of the replication, conducted also in this case with undergraduate students, confirms the results of the original experiment with slight differences, thus confirming that screen mockups facilitate the understanding of requirements without influencing the effort. We also sketch here some issues related to the documentation and communication between experimenters.