Assessment Comparable Score

Weight comparable assessments by caller-assigned similarity and measure the subject variance.

Description

A comparable-assessment score weights supplied values by similarity weights.

A comparable-assessment score weights supplied values by similarity weights. The subject difference is expressed relative to that weighted value, rather than as a statistical variance.^[1]

Weight comparable assessments by caller-assigned similarity and measure the subject variance.

When to use Assessment Comparable Score

Use this tool to weight comparable assessments by caller-assigned similarity and measure the subject variance.

Choose the specific arithmetic or checklist scenario and establish its input amounts, dates, rates and criteria from the applicable records. Keep currencies, periods and jurisdictions consistent; review the tool-specific assumptions before interpreting the result.

How to use Assessment Comparable Score and understand its results

Choose the specific arithmetic or checklist scenario and establish its input amounts, dates, rates and criteria from the applicable records. Keep currencies, periods and jurisdictions consistent; review the tool-specific assumptions before interpreting the result.
Enter subjectValue, comparableValues, similarityScores using the field table and calculation rules, then run the tool.
Read weightedComparableValue, subjectVariancePercent, totalWeight. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
subjectValue	Subject assessed value (currency)	number; minimum: 0	Required
comparableValues	Comparable assessed values (currency)	list of number	Required
similarityScores	Comparable similarity scores	list of number	Required

Enter aligned nonempty signed comparable values, nonnegative weights with positive total, and the subject value under its field constraints. Return weighted estimate and relative percentage; zero weighted estimate returns zero percentage.

weighted=Σ(value×weight)/Σweight; relativeDifference%=100(subject/weighted−1)

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
weightedComparableValue	Weighted comparable value (currency)	number; minimum: 0
subjectVariancePercent	Subject variance from comparables (%)	number
totalWeight	Total similarity weight	number; minimum: 0

json

{
  "input": {
    "subjectValue": 330000,
    "comparableValues": [
      300000,
      320000,
      340000
    ],
    "similarityScores": [
      1,
      2,
      1
    ]
  },
  "output": {
    "weightedComparableValue": 320000,
    "subjectVariancePercent": 3.125,
    "totalWeight": 4
  }
}

Limitations and assumptions

Similarity is supplied, not derived from property data. Individual comparables may be signed, but a negative weighted result is rejected by output validation. The percentage named subjectVariancePercent is a relative difference, not a variance statistic or independent appraisal.

Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use Land Productivity Rate Classifier: Classify land productivity using caller-supplied output, area, and rate threshold. For a complementary task, use TIF Revenue Increment: Calculate captured tax-increment revenue from caller-supplied values and rates.

References

Assessment Comparable Score — tool.io

Similar or alternative tools

Land Productivity Rate Classifier
Classify land productivity using caller-supplied output, area, and rate threshold.
TIF Revenue Increment
Calculate captured tax-increment revenue from caller-supplied values and rates.