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Evaluation Using Interface

Input:

  • Required Inputs:
    • expected_response: The reference answer column.
    • response: The generated answer column.
  • Configuration Parameters:
    • Comparator: The method used for comparison (e.g., Cosine, Exact Match).
    • Failure Threshold: Float (e.g., 0.7) - The similarity score below which the evaluation is considered a failure.

Output:

  • Score: Percentage score between 0 and 100

Interpretation:

  • Scores ≥ (Failure Threshold * 100): Indicate that the generated response is sufficiently similar to the expected_response based on the chosen Comparator.
  • Scores < (Failure Threshold * 100): Suggest that the response deviates significantly from the expected_response.

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Evaluation Using Python SDK

Click here to learn how to setup evaluation using the Python SDK.

Input TypeParameterTypeDescription
Required Inputsexpected_responsestringThe reference answer.
responsestringThe generated answer.
Configuration ParameterscomparatorstringThe method to use for comparison (e.g., Comparator.COSINE.value).
failure_thresholdfloatThe threshold below which the evaluation fails (e.g., 0.7).
Comparator NameClass Name
Cosine SimilarityComparator.COSINE.value
Jaccard SimilarityComparator.JACCARD.value
Normalised Levenshtein SimilarityComparator.NORMALISED_LEVENSHTEIN.value
Jaro Winckler similarityComparator.JARO_WINKLER.value
Sorensen Dice similarityComparator.SORENSEN_DICE.value
OutputTypeDescription
ScorefloatReturns a score between 0 and 1. Values ≥ failure_threshold indicate sufficient similarity.
from fi.evals import EvalClient
from fi.testcases import LLMTestCase
from fi.evals.templates import AnswerSimilarity
from fi.evals.types import Comparator

similarity_eval = AnswerSimilarity(config={
    "comparator": Comparator.COSINE.value,
    "failure_threshold": 0.8
})

test_case = LLMTestCase(
    response="example response",
    expected_response="example of expected response"
)

evaluator = EvalClient()
result = evaluator.evaluate(eval_templates=[similarity_eval], inputs=[test_case])
similarity_score = result.eval_results[0].metrics[0].value

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What to Do When Answer Similarity Evaluation is Low

A response review should be conducted to reassess the actual response’s alignment with the expected response and identify discrepancies. If necessary, a comparator adjustment can be made, selecting an alternative similarity measure that better captures nuanced differences in meaning.

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Differentiating Answer Similarity with Context Relevance

Answer Similarity specifically measures how closely two responses align in meaning, whereas Context Sufficiency determines whether a given context provides enough information to answer a query.

From an input perspective, Answer Similarity requires both an expected and actual response for comparison, while Context Sufficiency evaluates a query against its provided context.

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