Try the randomization demo
Our IVR and web products use an adaptive algorithm to randomly assign subjects with 4 prognostic factors (gender, age, education, doctor visit) into 3 cohorts, with balanced distribution in all 4 qualification areas.
IVR and Web use the same database for multi-modal use.
Feel free to try it out - the data is all just test data. Use 3-digit subject IDs.
For real projects:
Any number of qualification questions can be used.
Qualification questions may have any number of possible answers.
The number of cohorts is also not limited.
For example, you could randomize a sample of 65,000 subjects into 7 cohorts randomized by race, age decade, blood type, and several aspects of medical history.