On the value of acceptance tests

We've been chugging through the creation of a large set of acceptance tests for our major project for AIHW. What's been fascinating is how valuable it is to write the acceptance tests, not just use them. To date, we've been using them to help carry out quality assurance testing when we do a new release (typically every three weeks). The value in writing them has been for retrospectively reviewing the use cases of the user requirements specifications. 

While the user requirements went through several iterations and has been considered carefully by at least 3 people over several months, there have still been anomalies and inconsistencies in how the system was intended to work. Given the system is complex (several person years effort), this is not surprising. The acceptance tests effectively provide a new lens through which to examine the user requirements.

What this suggests to me is that having multiple ways to view your information has intrinsic value from a validation perspective. Dave Pollard has been discussing using the Wisdom of Crowds to help validate decisions and analysis. Simply providing new ways for an individual to view the same information - perhaps just presented in a different way - provides another mechanism to take a fresh perspective on its value and correctness. This perhaps is the heart of why crowds work well, by bringing together very rapidly multiple different perspectives to the same information.