CONTENTS 11.1 Summary 214 11.2 A Brief History of Galaxy Morphology 214 11.3 Genesis of Galaxy Zoo 217 11.4 Galaxy Zoo 1 219

11.4.1 From Clicks to Classifications 219 Classification Biases 220 Comparison with Other Classifications 220

11.4.2 Science Results from Galaxy Zoo 1 221 Color and Morphology 222 Spiral Arm Directions 222 Merging Galaxies 222 Active Galaxies 222 Rare and Unusual Objects 223

11.5 Evolution of Galaxy Zoo 223 11.5.1 Galaxy Zoo 2 and Hubble Zoo 223 11.5.2 The Citizen Scientists: Motivation and Unexpected Outcomes 224

11.6 The Zooniverse 226 11.6.1 Tasks Suitable for the Zooniverse 228 11.6.2 Data Mining the Zooniverse Results 230 11.6.3 Future Citizen Science Projects 230

11.7 Galaxy Zoo in the Context of Other Citizen Science Projects 232 11.8 Conclusions 233 References 233

11.1 SUMMARY We provide a brief overview of the Galaxy Zoo and Zooniverse projects, including a short discussion on the history of, and motivation for, these projects as well as reviewing the science these innovative Internet-based citizen science projects have produced so far. We briefly describe the method of applying en-masse human pattern recognition capabilities to complex data in data-intensive research. We also provide a discussion on the lessons learned from developing and running these community-based projects including thoughts on future applications of this methodology. This review is intended to give the reader a quick and simple introduction to the Zooniverse.