Hallucination

OPENAI_API_KEY=your_api_key_here

import { openai } from "@ai-sdk/openai";
import { HallucinationMetric } from "@mastra/evals/llm";

const context1 = [
  "The iPhone was first released in 2007.",
  "Steve Jobs unveiled it at Macworld.",
  "The original model had a 3.5-inch screen.",
];
 
const metric1 = new HallucinationMetric(openai("gpt-4o-mini"), {
  context: context1,
});
 
const query1 = "When was the first iPhone released?";
const response1 =
  "The iPhone was first released in 2007, when Steve Jobs unveiled it at Macworld. The original iPhone featured a 3.5-inch screen.";
 
console.log("Example 1 - No Hallucination:");
console.log("Context:", context1);
console.log("Query:", query1);
console.log("Response:", response1);
 
const result1 = await metric1.measure(query1, response1);
console.log("Metric Result:", {
  score: result1.score,
  reason: result1.info.reason,
});
// Example Output:
// Metric Result: { score: 0, reason: 'The response matches the context exactly.' }

const context2 = [
  "The first Star Wars movie was released in 1977.",
  "It was directed by George Lucas.",
  "The film earned $775 million worldwide.",
  "The movie was filmed in Tunisia and England.",
];
 
const metric2 = new HallucinationMetric(openai("gpt-4o-mini"), {
  context: context2,
});
 
const query2 = "Tell me about the first Star Wars movie.";
const response2 =
  "The first Star Wars movie came out in 1977 and was directed by George Lucas. It made over $1 billion at the box office and was filmed entirely in California.";
 
console.log("Example 2 - Mixed Hallucination:");
console.log("Context:", context2);
console.log("Query:", query2);
console.log("Response:", response2);
 
const result2 = await metric2.measure(query2, response2);
console.log("Metric Result:", {
  score: result2.score,
  reason: result2.info.reason,
});
// Example Output:
// Metric Result: { score: 0.5, reason: 'The response contradicts some facts in the context.' }

const context3 = [
  "The Wright brothers made their first flight in 1903.",
  "The flight lasted 12 seconds.",
  "It covered a distance of 120 feet.",
];
 
const metric3 = new HallucinationMetric(openai("gpt-4o-mini"), {
  context: context3,
});
 
const query3 = "When did the Wright brothers first fly?";
const response3 =
  "The Wright brothers achieved their historic first flight in 1908. The flight lasted about 2 minutes and covered nearly a mile.";
 
console.log("Example 3 - Complete Hallucination:");
console.log("Context:", context3);
console.log("Query:", query3);
console.log("Response:", response3);
 
const result3 = await metric3.measure(query3, response3);
console.log("Metric Result:", {
  score: result3.score,
  reason: result3.info.reason,
});
// Example Output:
// Metric Result: { score: 1, reason: 'The response completely contradicts the context.' }