The Most Common Prompt Mistakes

Knowledge

Even with the best LLM, you will get poor results if your prompt is bad. Here are the five most common mistakes beginners make -- and how to avoid them.

Mistake 1: Too vague Bad: "Write me something about AI." Better: "Write 5 bullet points about the most important applications of AI in healthcare."

Mistake 2: Too many tasks at once Bad: "Explain AI to me, write an email to my boss, and find a good restaurant in Berlin." Better: Ask each task separately. One prompt = one task.

Mistake 3: No format specification Bad: "What are the advantages of working from home?" Better: "List the 5 most important advantages of working from home as a numbered list with one sentence of explanation each."

Mistake 4: Not checking for hallucinations LLMs sometimes make up things that sound convincing but are wrong. These are called hallucinations. They cite studies that do not exist or state facts that are entirely fabricated.

Mistake 5: Not providing context Bad: "Write a letter." Better: "Write a formal letter to the building management about water damage in my apartment. I have been a tenant for 3 years."

Understand

Recognizing Hallucinations

Hallucinations are especially dangerous because they are so convincingly worded. An LLM never writes "I am not quite sure, but..." -- it presents fabricated facts with the same confidence as real ones.

Pay special attention to:

• Specific numbers and statistics -- often made up
• Quotes and sources -- frequently nonexistent
• Historical details -- sometimes mixed up or wrong

A useful tip: Ask the LLM to name its sources. Then check whether those sources actually exist. If the LLM says "According to a Harvard study from 2023...," google exactly that. You will often find that the study does not exist.

Apply

Ask an LLM a factual question, for example: "What studies support the benefits of meditation?" Then check three of the cited sources with a search engine. How many of them actually exist?

Reflect