1. INTRODUCTION

2. QUALITY IN CROWDSOURCING  
2.1. Taxonomy  
2.2. Literature Selection  

3. CROWDSOURCING QUALITY MODEL  

4. QUALITY ASSESSMENT  
4.1. Individual Assessments  
4.2. Group Assessments  
4.3. Computation-based Assessments  

5. QUALITY ASSURANCE  

6. ANALYSIS OF STATE-OF-THE-ART CROWDSOURCING PLATFORMS  

7. CONCLUSION AND OUTLOOK