The obvious explanation (in my mind) for why “open data” gets so much attention in the context of “open government” is that it is the sexiest, flashiest reform of the bunch. It’s much cooler (and frankly less politically controversial) for any government to put government health databases online (along with an iPhone app! Android coming soon!) than it is for the same government to provide greater transparency around the financing of political parties in the country.

The open data movement is clearly still in its infancy and major successes may be yet to come. But in the interim, some caution may be in order before we launch a global campaign to liberate every last bit of government data out there, especially in lower-income contexts where the opportunity costs may be massive. -

- from Is Open Data a Good Idea for the Open Government Partnership? at Global Integrity

By focusing primarily on outputs (projects, apps, data portals, etc) rather than outcomes (improved service delivery and the like) we risk losing momentum in a similar way to how the traditional transparency and accountability movement lost momentum: only after the fact coming to terms with whether we could trace real-life impact and demonstrate the power and efficacy of our values. The traditional anti-corruption and transparency movement came to this realization almost two decades late and is currently scrambling to invest in research and analysis to parse the outcomes from the output. I desperately hope the open government movement doesn’t make the same mistakes.

- from Outputs versus Outcomes in Open Government at Global Integrity