What must stay in working memory
- Category and function are independent axes: a technical control can be preventive, detective, or corrective.
- Classify by the immediate effect, not by every possible secondary benefit.
- A compensating control should address the original risk with comparable protection and be documented as an exception.
Concrete examples
- MFA is usually preventive; a failed-login alert is detective; restoring a known-good image is corrective.
- A warning banner deters, while a required-handling policy directs.
Decision rules you’ll retrieve
Classify a control's primary function
Use the control's immediate primary effect: instruct, discourage, block, discover, restore, or substitute for an unavailable requirement.
Retrieval cue: Name the six common functional control types and give a one-verb test for each.
Choose a defensible compensating control
When the required control cannot be used, choose a documented, time-bounded alternative that reduces the same risk—not merely a convenient unrelated safeguard.
Retrieval cue: State the test that makes an alternative safeguard a compensating control rather than an unrelated extra control.
Distinguish deterrent, preventive, and detective effects
Discouragement is deterrent, enforced blocking is preventive, and evidence or alerting that reveals an event is detective.
Retrieval cue: For one attempted intrusion, describe what a deterrent, preventive, and detective control would each do at a different moment.