A clinical Research Study may be Online or offline. An online study means volunteers participation in Clinical Trial Study is posted online and offline Study means volunteers participation is not posted online.As per Rules Volunteers are not allowed to take part in any study for 90 days from the date of completion of any study including Blood donation. So to avoid multi participation in study by volunteer, Clinical Research Labs check/Put study participation in Online Volunteer Information System (OVIS) with Finger/Fingers.OVIS is the most common application used by Indian Labs for checking and put study participation of volunteer online. OVIS is/can only accessed by CRO (Labs) and other concerned authorities. So volunteer need not to worry about privacy, also Only Name/Initials/Photo/Finger Impressions are registered in OVIS.Mostly, Volunteer's Thumbs and Index fingers are checked by the lab in OVIS but labs can put your participation online in OVIS with any finger/Fingers, which is also called offline study apart from not putting online.Offline study generally means that Lab will not put any detail of volunteer's study participation online in OVIS or may put study participation in some other application which is used by only few labs.Labs can check Volunteer's info in OVIS at the time of screening and checkin but will post your participation online only when your dosing has been done.There is also an alternate to OVIS used by many Labs , BLUMEDHA. Blumedha software is used by so many labs now a days and it works same as OVIS but if you are online in OVIS it won't be shown in Blumedha and vice versa.Only Labs in Karnataka (Bangalore & Accunova Lab) and Mumbai will post your study participation with Thumb.Few Study Labs where Blumedha is used:1. Biocon Lab Bangalore 2. Apotex Lab Bangalore 3. Micro Lab Bangalore 4. Accunova Lab Manglore & Uduppi5. Jeevan Lab Hyderabad6. Aizant Lab Hyderabad7. Zenrise Lab Hyderabad8. Sitech Lab MumbaiSo to make more money from study in India, you need to know which lab is posting your study participation online and which lab not. In layman language or volunteer's language, it is referred as Net check and posting on net.StudyBlood has given information about online/offline study by lab in almost each lab info post.