Does Image search in-scope or out-of-scope for this project? Because I have issues with specifically image search result, in multiple projects: Commons, Wikipedia, and more recently Wikistories, which get the result from the Commons, albeit with some additional filters. One of them is lack of user participation in the result algorithm, where if the algorithm puts some images at the top but not suitable for the topic, users should be able to do something about them (vote them down for that keyword).
Having said that and wrote this, I guess the same could be implemented to (article) search result and user interaction, where users could vote up or vote down certain result for any given keywords.