  Establishing a shared software project vision is a key challenge in
Requirements Engineering (RE). Several approaches use videos to represent
visions. However, these approaches omit how to produce a good video. This
missing guidance is one crucial reason why videos are not established in RE. We
propose a quality model for videos representing a vision, so-called vision
videos. Based on two literature reviews, we elaborate ten quality
characteristics of videos and five quality characteristics of visions which
together form a quality model for vision videos that includes all 15 quality
characteristics. We provide two representations of the quality model: (a) A
hierarchical decomposition of vision video quality into the quality
characteristics and (b) A mapping of these characteristics to the video
production and use process. While the hierarchical decomposition supports the
evaluation of vision videos, the mapping provides guidance for video
production. In an evaluation with 139 students, we investigated whether the 15
characteristics are related to the overall quality of vision videos perceived
by the subjects from a developer's the point of view. Six characteristics
(video length, focus, prior knowledge, clarity, pleasure, and stability)
correlated significantly with the likelihood that the subjects perceived a
vision video as good. These relationships substantiate a fundamental relevance
of the proposed quality model. Therefore, we conclude that the quality model is
a sound basis for future refinements and extensions.
