Crowdsourcing. Group thinking. Call it what you will, but in the past ten years, average Joes tasked with online assignments (from bird counting to cloud identification and more) have contributed reams of data to the scientific body. Just one thing: Few scientists ever took it seriously. That’s changed. Sites are better, questions keener, and citizens are becoming viable foot soldiers in legitimate scientific studies. “We have over 30 ornithology papers published in peer-reviewed journals that use volunteer-collected data,” says Rick Bonney of the Cornell Lab of Ornithology’s Citizen Science Program. Here are four ways you can lend a hand.