Unknown unknown
An unknown unknown is a relevant fact, condition, risk, knowledge gap, behavior, or failure possibility whose existence or possibility is not recognized.
Effective Platform Engineering
An unknown unknown is a relevant condition, behavior, or failure mode whose possibility has not previously been recognized.
- How it is used
- Guides observability practices toward discovering and resolving failures that monitoring has not anticipated.
- How deep it goes
- Explains discovery through telemetry, tracing, time-series analysis, and predictive models, but stops short of prescribing a specific technology.
- Examples
- Uses pod rescheduling, malformed API data, outages, overlapping dashboards, and outlier analysis as concrete failure and investigation examples.
- What you can do after
- Diagnose/debug with it by instrumenting systems, tracing transactions, correlating data, and analyzing anomalies to expose unfamiliar failure modes.
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Experimentation for Engineers
Factors affecting system performance that have not been considered because they are absent from the current model or knowledge.
- How it is used
- Frames experimentation as necessary when system complexity exceeds what domain knowledge and explicit models can capture.
- How deep it goes
- Defines unknown unknowns through signal, noise, and omitted factors, but does not develop a mitigation procedure.
- Examples
- Uses a Bing search change that generated more than $100 million in unexpected annual revenue.
- What you can do after
- Evaluate system changes with awareness that unmodeled factors may produce unexpectedly large positive or negative effects.
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Related concepts
- language modelused by · A language model is a computational model that represents patterns in linguistic tokens to estimate sequence probabilities and predict or generate language from context.
- confidenceproduces · Confidence is a degree of certainty or assurance associated with a judgment, estimate, prediction, capability, or statistical procedure, often expressed as a score, probability, or coverage level.
- known unknowncontrasts with · A known unknown is a potentially relevant fact or condition whose existence is recognized but whose behavior or details are not understood.
These guides are generated from the text of Manning books by Manning's knowledge graph and link to the sections they draw on. The full books are available on liveBook and at manning.com.