逐對摘要品質評估

這個範例會示範如何使用成對比較功能，評估兩個生成式 AI 模型的摘要品質。評估時會使用指標，評估各模型總結特定文字的成效。

深入探索

如需包含這個程式碼範例的詳細說明文件，請參閱下列內容：

• Gen AI 評估服務 API

程式碼範例

Go

在試用這個範例之前，請先按照Go使用用戶端程式庫的 Vertex AI 快速入門中的操作說明進行設定。 詳情請參閱 Vertex AI Go API 參考說明文件。

如要向 Vertex AI 進行驗證，請設定應用程式預設憑證。 詳情請參閱「為本機開發環境設定驗證」。

import (
	context_pkg "context"
	"fmt"
	"io"

	aiplatform "cloud.google.com/go/aiplatform/apiv1beta1"
	aiplatformpb "cloud.google.com/go/aiplatform/apiv1beta1/aiplatformpb"
	"google.golang.org/api/option"
)

// pairwiseEvaluation lets the judge model to compare the responses of two models and pick the better one
func pairwiseEvaluation(w io.Writer, projectID, location string) error {
	// location = "us-central1"
	ctx := context_pkg.Background()
	apiEndpoint := fmt.Sprintf("%s-aiplatform.googleapis.com:443", location)
	client, err := aiplatform.NewEvaluationClient(ctx, option.WithEndpoint(apiEndpoint))

	if err != nil {
		return fmt.Errorf("unable to create aiplatform client: %w", err)
	}
	defer client.Close()

	context := `
As part of a comprehensive initiative to tackle urban congestion and foster
sustainable urban living, a major city has revealed ambitious plans for an
extensive overhaul of its public transportation system. The project aims not
only to improve the efficiency and reliability of public transit but also to
reduce the city\'s carbon footprint and promote eco-friendly commuting options.
City officials anticipate that this strategic investment will enhance
accessibility for residents and visitors alike, ushering in a new era of
efficient, environmentally conscious urban transportation.
`
	instruction := "Summarize the text such that a five-year-old can understand."
	baselineResponse := `
The city wants to make it easier for people to get around without using cars.
They're going to make the buses and trains better and faster, so people will want to
use them more. This will help the air be cleaner and make the city a better place to live.
`
	candidateResponse := `
The city is making big changes to how people get around. They want to make the buses and
trains work better and be easier for everyone to use. This will also help the environment
by getting people to use less gas. The city thinks these changes will make it easier for
everyone to get where they need to go.
`

	req := aiplatformpb.EvaluateInstancesRequest{
		Location: fmt.Sprintf("projects/%s/locations/%s", projectID, location),
		MetricInputs: &aiplatformpb.EvaluateInstancesRequest_PairwiseSummarizationQualityInput{
			PairwiseSummarizationQualityInput: &aiplatformpb.PairwiseSummarizationQualityInput{
				MetricSpec: &aiplatformpb.PairwiseSummarizationQualitySpec{},
				Instance: &aiplatformpb.PairwiseSummarizationQualityInstance{
					Context:            &context,
					Instruction:        &instruction,
					Prediction:         &candidateResponse,
					BaselinePrediction: &baselineResponse,
				},
			},
		},
	}

	resp, err := client.EvaluateInstances(ctx, &req)
	if err != nil {
		return fmt.Errorf("evaluateInstances failed: %v", err)
	}

	results := resp.GetPairwiseSummarizationQualityResult()
	fmt.Fprintf(w, "choice: %s\n", results.GetPairwiseChoice())
	fmt.Fprintf(w, "confidence: %.2f\n", results.GetConfidence())
	fmt.Fprintf(w, "explanation:\n%s\n", results.GetExplanation())
	// Example response:
	// choice: BASELINE
	// confidence: 0.50
	// explanation:
	// BASELINE response is easier to understand. For example, the phrase "..." is easier to understand than "...". Thus, BASELINE response is ...

	return nil
}

Python

在試用這個範例之前，請先按照Python使用用戶端程式庫的 Vertex AI 快速入門中的操作說明進行設定。 詳情請參閱 Vertex AI Python API 參考說明文件。

如要向 Vertex AI 進行驗證，請設定應用程式預設憑證。 詳情請參閱「為本機開發環境設定驗證」。

import pandas as pd

import vertexai
from vertexai.generative_models import GenerativeModel
from vertexai.evaluation import (
    EvalTask,
    PairwiseMetric,
    MetricPromptTemplateExamples,
)

# TODO(developer): Update & uncomment line below
# PROJECT_ID = "your-project-id"
vertexai.init(project=PROJECT_ID, location="us-central1")

prompt = """
Summarize the text such that a five-year-old can understand.

# Text

As part of a comprehensive initiative to tackle urban congestion and foster
sustainable urban living, a major city has revealed ambitious plans for an
extensive overhaul of its public transportation system. The project aims not
only to improve the efficiency and reliability of public transit but also to
reduce the city\'s carbon footprint and promote eco-friendly commuting options.
City officials anticipate that this strategic investment will enhance
accessibility for residents and visitors alike, ushering in a new era of
efficient, environmentally conscious urban transportation.
"""

eval_dataset = pd.DataFrame({"prompt": [prompt]})

# Baseline model for pairwise comparison
baseline_model = GenerativeModel("gemini-2.0-flash-lite-001")

# Candidate model for pairwise comparison
candidate_model = GenerativeModel(
    "gemini-2.0-flash-001", generation_config={"temperature": 0.4}
)

prompt_template = MetricPromptTemplateExamples.get_prompt_template(
    "pairwise_summarization_quality"
)

summarization_quality_metric = PairwiseMetric(
    metric="pairwise_summarization_quality",
    metric_prompt_template=prompt_template,
    baseline_model=baseline_model,
)

eval_task = EvalTask(
    dataset=eval_dataset,
    metrics=[summarization_quality_metric],
    experiment="pairwise-experiment",
)
result = eval_task.evaluate(model=candidate_model)

baseline_model_response = result.metrics_table["baseline_model_response"].iloc[0]
candidate_model_response = result.metrics_table["response"].iloc[0]
winner_model = result.metrics_table[
    "pairwise_summarization_quality/pairwise_choice"
].iloc[0]
explanation = result.metrics_table[
    "pairwise_summarization_quality/explanation"
].iloc[0]

print(f"Baseline's story:\n{baseline_model_response}")
print(f"Candidate's story:\n{candidate_model_response}")
print(f"Winner: {winner_model}")
print(f"Explanation: {explanation}")
# Example response:
# Baseline's story:
# A big city wants to make it easier for people to get around without using cars! They're going to make buses and trains ...
#
# Candidate's story:
# A big city wants to make it easier for people to get around without using cars! ... This will help keep the air clean ...
#
# Winner: CANDIDATE
# Explanation: Both responses adhere to the prompt's constraints, are grounded in the provided text, and ... However, Response B ...

後續步驟

如要搜尋及篩選其他 Google Cloud 產品的程式碼範例，請參閱Google Cloud 範例瀏覽器。