People have written code that can help you.
Because Zooniverse projects hosted on the Panoptes platform share a codebase, their outputs should be similar in format. That means that code written by other researchers to aggregate contributions from other users, and perhaps also to weight different users by their performance, may work for your projects too. There is a collection of such code available here: https://github.com/vrooje/panoptes_analysis and here https://github.com/zooniverse/Data-digging in repositories curated by Brooke Simmons (Lancaster University/Galaxy Zoo).
For details of more complex analysis, we suggest looking at papers by teams behind Space Warps (http://mnras.oxfordjournals.org/content/455/2/1171.full.pdf) or Snapshot Serengeti (http://onlinelibrary.wiley.com/doi/10.1111/cobi.12695/abstract).