Precision & intervals

A valuation is an estimate of the asking-price market for one vehicle, not a guaranteed transaction price, settlement value or offer to buy. This page explains the parts of a result that tell you how far to rely on it, and how to present them.

#The price and its basis

valuation.price is a point estimate in valuation.currency for valuation.price_basis:

Neither is a trade-in price or a final sale price. Always show the price with its currency and price_basis_description, which is written for display.

#Uncertainty intervals

valuation.intervals gives ranges around the estimate at three coverage levels:

{
  "intervals": [
    { "coverage": 0.8, "low": 82138, "high": 123208, "method": "synthetic" },
    { "coverage": 0.95, "low": 66737, "high": 138609, "method": "synthetic" },
    { "coverage": 0.99, "low": 51337, "high": 154010, "method": "synthetic" }
  ]
}

coverage is the intended share of comparable vehicles whose market price falls inside the range: about 80% for the first, 95% and 99% for the others. It describes the model's calibration across many vehicles. It is not a guarantee for one particular car.

• Show the 80% interval as the everyday range ("most comparable cars are listed between ..."). Use the wider ones for risk decisions such as lending limits.
• A narrow interval with a weak precision grade is still a weak result. Read them together.
• method says how the interval was produced: calibrated when it is calibrated against observed market outcomes, estimated otherwise. Test results use synthetic.

#The precision grade

precision.grade combines the model's own uncertainty with how well the vehicle was identified:

A broad catalogue match, an assumed mileage or a missing important attribute lowers the grade. An assumed mileage (the 96,000 km baseline) or assumed equipment (options.allow_equipment_estimation) caps it at low. precision.summary explains the grade in a sentence you can show.

If you cannot use a result below a certain grade, send options.min_precision. A result below it is refused with precision_below_minimum, for free, and the refusal lists what to add. See improve precision.

#Other precision fields

#Price ratings

price_ratings.bands divides the price range into AutoUncle's five price ratings for this vehicle:

Each band has from and to prices in the market currency. Send pricing.asking_price to have a listing rated: the result then includes asking_price_rating and asking_price_label.

stable_within_80pct_interval tells you whether that rating holds anywhere in the 80% interval. When it is false, the rating could change if the true market value sits elsewhere in the interval; present it with care, for example as "around a good price". Without an asking price, all three fields are null.

#Warnings and hints

warnings reports problems with this request's input, such as generation_ambiguous, equipment_not_recognized, images_not_used or km_imputed. improve_precision lists the inputs that would make the result more precise, each with an expected_impact of high, medium or low. The impact is qualitative: it does not promise that the price or the interval changes by a fixed amount. See improve precision.

#Presenting a valuation

A good display has, at minimum:

1. The price with currency and the price basis description.
2. The 80% interval.
3. The precision grade or summary.
4. The resolved vehicle, so the reader can see which car was valued.
5. Any attribution_text, and the notes that apply (see show notes & attributions).

Avoid wording such as "worth", "offer" or "guaranteed". Prefer "estimated asking price" and "most comparable cars are listed between ...". Never show a test-key result to end users: it is simulated, always indicative and carries a synthetic_result note.