@pasafasoru Dear Jose, A few additional resources in brief.
Here’s a link to work by Julia Keseru on evaluating the impact of Open Data.
Here’s the Common Assessment Framework jointly developed by various parties:
There’s a community that meets to discuss open data research every year.
In addition to the various rubrics for measuring the comprehensiveness and quality of data or the availability of certain datasets necessary in a democracy (e.g. the President’s tax returns) or to solve particular problems (e.g. public spending and contracting data that’s essential for reducing corruption in public procurement), ultimately, I believe, the metrics need to focus on the problem you are trying to solve. The open data is the means to the end. We should keep our focus on improving people’s lives, whether the strength of democracy or the cost of healthcare or access to education and look at open data’s role in enabling those goals.