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ReferenceScorersContentSimilarity

Content Similarity Scorer

The createContentSimilarityScorer() function measures the textual similarity between two strings, providing a score that indicates how closely they match. It supports configurable options for case sensitivity and whitespace handling.

For a usage example, see the Content Similarity Examples.

Parameters

The createContentSimilarityScorer() function accepts a single options object with the following properties:

ignoreCase:

boolean
= true
Whether to ignore case differences when comparing strings.

ignoreWhitespace:

boolean
= true
Whether to normalize whitespace when comparing strings.

This function returns an instance of the MastraScorer class. See the MastraScorer reference for details on the .run() method and its input/output.

.run() Returns

runId:

string
The id of the run (optional).

extractStepResult:

object
Object with processed input and output: { processedInput: string, processedOutput: string }

analyzeStepResult:

object
Object with similarity: { similarity: number }

score:

number
Similarity score (0-1) where 1 indicates perfect similarity.

Scoring Details

The scorer evaluates textual similarity through character-level matching and configurable text normalization.

Scoring Process

  1. Normalizes text:
    • Case normalization (if ignoreCase: true)
    • Whitespace normalization (if ignoreWhitespace: true)
  2. Compares processed strings using string-similarity algorithm:
    • Analyzes character sequences
    • Aligns word boundaries
    • Considers relative positions
    • Accounts for length differences

Final score: similarity_value * scale

Score interpretation

(0 to scale, default 0-1)

  • 1.0: Perfect match - identical texts
  • 0.7-0.9: High similarity - mostly matching content
  • 0.4-0.6: Moderate similarity - partial matches
  • 0.1-0.3: Low similarity - few matching patterns
  • 0.0: No similarity - completely different texts
CompletenessFaithfulness