The Strangeness/Probability Matrix
Last update: 19 May 2022
The criteria that follow are subject to continual refinement. When trying to make the seemingly unmeasureable measurable, you often have to iterate. We’re not moving the goal posts, just making them easier to find.
Both strangeness and probability are rated on 0-5 scales. Where a particular case is placed on each scale can be governed by broad guidelines, but it is ultimately up to the judgment of the investigator. The thing to keep in mind is the upper right hand corner of the matrix are the cases most deserving thorough follow-up investigation. Therefore, we recommend assigning preliminary P/S matrix position and possibly changing it as the investigation proceeds.
Probability isn’t probability in the mathematical sense, but instead attempts to quantify the extent to which the data in the report is credible -in other words, it is a case quality rating. Strangeness is the degree to which the the report and any supporting evidence describe behavior, structure and experiences that defy conventional explanation – without reference to how credible the evidence is. Reports can have high strangeness and low probability, high probability and low strangeness, or both. What follows are API’s guidelines for each.
Probability
Probability isn’t just an assessment of witness credibility, but about the quantity, independence, and quality of the evidence.
0 – Strong evidence of a hoax or hallucination. Witness credibility demonstrably low.
1 – Little difference between the report and a fictional story: only a single witness willing to come forth, no physical evidence confirmed by investigation, no corroboration, no contemporaneous notes, sketches, photographs or videos. Photographs or videos, if they exist, do not have clear provenance, metadata, or context.
2 – Single, cooperative witness with contemporaneous notes, sketches or sighting reports. Possibly a second witness, but not a strong corroboration, or considerable collusion on the story before discussion with investigators. All evidence supported by investigative findings. Photos or videos appear to corroborate witness observations, but show little additional information.
3 – Multiple credible witness reports within short time of the sighting with good consistency between witnesses. Contemporaneous notes and sketches. Photographs or videos with clear provenance and useful metadata or context. Photographs have metadata consistent with testimony and have been subjected to careful analysis. Witnesses do not seek publicity. All evidence supported by investigative findings.
4 – All criteria of (3), plus a high degree of independence between credible witnesses. More than 1 video or photograph with clear provenance and metadata at the same time from multiple observers. Physical evidence subjected to analysis. Thorough investigation conducted shortly after the event.
5 – Both remote sensing (e.g. RADAR, optical) and well-documented in-situ physical evidence with clear chains of custody from highly credible sources in addition to the criteria of 4.
Strangeness
0 – With high probability a well-known and understood natural or human-made phenomenon such as a bright planet, Chinese lantern, lenticular cloud, meteor, or aircraft landing lights.
1 – Possibly a known human-made or natural object if one aspect of the report is misreported or misperceived.
2 – At least one significant aspect of the report is highly puzzling.
3 – The report consistently describes behavior and appearance of an object or objects that defies conventional explanation. Multiple puzzling observations.
4 – The report meets the criteria of three, plus indicates interaction with the witness, animals or the environment, such as landing traces, interference with equipment, or communication.
5 – Report meets some of the criteria of 4, plus additional strange and inexplicable aspects such as repetition of events, missing time or time distortion, artifacts, added time, implants, or other highly strange phenomena.