There are various roles in the field of clinical research.
The following is the list of some of the roles and responsiblities which could be part of various fields of Clinical Resarch.
1. Clinical Research Associates
2. Clinical Research Team Lead
3. Clinical Development Manager
4. Clinical Database Designer
5. Clinical Data Entry Operator
6. Clinical Data Validator
7. Clinical Statistician
8. SAS Programer
9. Data Manager/ Lead Data Manager
10. Medical Writer
11. Clinical Study Co-ordinator
12. Clinical Research Protocal Manager
13. Medical Affairs Manager
14. Clinical Research Quality Contoller
15. Many more...
Also Check out this link for more detailed description about clinical research roles.