In general, VCSs provide an interesting playground for experiments in the psychology of programming.
They have many of the same usability properties of programming languages, but
without the extremely high implementation costs and challenges to external validity. VCSs play
a central role in much software development practice, and they have much to offer to other
disciplines. However, we have shown that with their current design, they have very problematic
usability, even for professional software engineers. They represent an example where expertise
alone is insufficient to give confidence, and have a long way to go before offering ’development
without fear’. This is an example of the additional concerns beyond the strictly computational
that must be addressed before the transfer of technology from Computer Science to a wider
population can be successful.