Evaluate model performance

This sample code demonstrates how to evaluate the performance of a GenAI model. It showcases how to define the evaluation specification, evaluate the model, and retrieve the evaluation metrics.

Explore further

For detailed documentation that includes this code sample, see the following:

• Run a computation-based evaluation pipeline

Code sample

Python

Before trying this sample, follow the Python setup instructions in the Vertex AI quickstart using client libraries. For more information, see the Vertex AI Python API reference documentation.

To authenticate to Vertex AI, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

import os

from google.auth import default

import vertexai
from vertexai.preview.language_models import (
    EvaluationTextClassificationSpec,
    TextGenerationModel,
)

PROJECT_ID = os.getenv("GOOGLE_CLOUD_PROJECT")


def evaluate_model() -> object:
    """Evaluate the performance of a generative AI model."""

    # Set credentials for the pipeline components used in the evaluation task
    credentials, _ = default(scopes=["https://www.googleapis.com/auth/cloud-platform"])

    vertexai.init(project=PROJECT_ID, location="us-central1", credentials=credentials)

    # Create a reference to a generative AI model
    model = TextGenerationModel.from_pretrained("text-bison@002")

    # Define the evaluation specification for a text classification task
    task_spec = EvaluationTextClassificationSpec(
        ground_truth_data=[
            "gs://cloud-samples-data/ai-platform/generative_ai/llm_classification_bp_input_prompts_with_ground_truth.jsonl"
        ],
        class_names=["nature", "news", "sports", "health", "startups"],
        target_column_name="ground_truth",
    )

    # Evaluate the model
    eval_metrics = model.evaluate(task_spec=task_spec)
    print(eval_metrics)
    # Example response:
    # ...
    # PipelineJob run completed.
    # Resource name: projects/123456789/locations/us-central1/pipelineJobs/evaluation-llm-classification-...
    # EvaluationClassificationMetric(label_name=None, auPrc=0.53833705, auRoc=0.8...

    return eval_metrics

What's next

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