A map of the failure modes

The SSGM paper organizes memory failures into four dimensions, which is a clean way to hold the whole landscape in mind:

• Stability failures: the knowledge slowly deviates from the truth (drift).
• Validity failures: the stored content is wrong or out of date (hallucination, obsolescence).
• Efficiency failures: the memory becomes too big or too slow.
• Safety failures: the memory is attacked or leaks (poisoning, privacy).

The "Practical Guide" groups its examples slightly differently (context-resident, retrieval, knowledge-integrity, and environmental), but the underlying failures line up. The sections below walk through them by theme.