If a student fails to pass master's exams, comprehensive exams, or qualifying examinations, cannot form a master’s thesis or doctoral committee, or fails to meet other departmental milestones or University standards, the Department Chair or Graduate Advisor may recommend monitoring status, academic probation, or academic disqualification to the Graduate Dean.
https://www.graddiv.ucsb.edu/policy-procedure/academic-performance-and-progress#Performance-Standard
Usually students are placed on monitoring status for at least one quarter before being escalated to probation (since a consequence of probation is the loss of funding/employment)
In certain circumstances it may be appropriate to place a student on probation without a quarter of monitoring first, such as when a student fails the first attempt at a qual/comp exam, and only has one attempt left.
Please read this documentation as well: https://ucsb-atlas.atlassian.net/l/c/aEvXf19u