At the start of the registration process, participants are asked to self-select into their own “sub-subjectpool”. This page will only show up if different sub-subjectpools are defined in the system. Sub-subjectpools are useful because they provide a tool to administrate different populations, for instance mailing lists for Internet experiments only, or laboratory subjects in different cities, or alumni vs. current students. The profile registration page can differ conditional on the selected subject pool, which allows to maintain subject pools at different institutions within the same ORSEE installation, or to sharply distinguish between students and other people (see also section Sub-subjectpools). Within the system, subjects can be migrated from one subject pool to the other.

After having selected their sub-subjectpool, potential participants are presented with the rules for experiments and the privacy policy (only if at least one of them were defined and enabled, see also section Rules). Subjects have to accept by clicking on the acceptance button at the bottom of the page. This confirmation initiates the display of the profile registration page.

On the profile registration page, subjects are asked to enter their personal data. This form can be freely customized within the system and so may differ from laboratory to laboratory. In the default version, foe example, only e-mail address, last name, and first name are compulsory. A text shown on the form could inform potential participants that providing additional information about themselves can lead to more invitations. Further demographics asked for may include gender, phone number, begin of study, field of study, profession, etc.

If the system is configured to use username/password for participant authentication, the form will also ask the subject to choose a password according to the set password strength rules. If URL-token are used for authentication, not such field appears.

Finally, the system asks the subject to copy the contents of a CAPTCHA into a text field, to protect the website against automated attacks.

After submitting the registration form, the system verifies the submitted data (depending on the form definition, but always including a check of the CAPTCHA and that the provided email address does not already exist), and the profile data will be written to the database. The subject receives an e-mail to the provided email address asking her to confirm her registration. The confirmation e-mail includes a link that leads to a page which informs the subject about the successful confirmation of their registration.

Every e-mail which participants receive from the system includes a link in the email footer which leads to the participant's profile page. On that page, a form similar to the registration form allows the subject to change his data or to unsubscribe from the subject pool and mailing list. However, to ensure database integrity, the account is not deleted completely. If the same subject later attempts to register again with the system, the system will recognizes the email address, and an experimenter can reactivate the account manually. At any time, an experimenter may delete personal data (e.g. on written request from the subject) by filling blanks into the participant profile.