Eminent computer scientist Ed Felten has posted a short, extremely useful taxonomy of four ways that an algorithm can fail to be accountable to the people whose lives it affects: it can be protected by claims of confidentiality ("how it works is a trade secret"); by complexity ("you wouldn't understand how it works"); unreasonableness ("we consider factors supported by data, even when you there's no obvious correlation"); and injustice ("it seems impossible to explain how the algorithm is consistent with law or ethics"). (more…)