Lesson 15. Which AI model to choose for a task?
There's no single 'best' AI model. GPT-4o, Claude 3.5 Sonnet, Gemini 1.5 Pro — each was built for different purposes and gives different results on different tasks. Choosing the right model often affects quality more than improving the prompt.
Topic breakdown
The same prompt on different models can produce different results. This doesn't mean the model is bad — each is built on different architecture, training data, and target tasks.
GPT-4o is universal and fast. Claude excels at long documents and nuanced writing style. Gemini is strong for Google integration and up-to-date information. Open models are for confidential data and API cost savings.
Price matters too. GPT-4o and Claude 3.5 Sonnet are premium. Gemini Flash, Claude Haiku, GPT-4o mini are cheaper and often powerful enough.
Best approach: test one task on 2-3 models and compare results. This takes time but significantly simplifies decision-making.
What you'll learn
- know the main differences between GPT-4o, Claude, Gemini, and open models
- understand criteria for choosing a model for a task
- test the same prompt on different models
- evaluate price-to-quality ratio
Lesson plan
GPT-4o: the universal choice
Fast, multimodal, wide ecosystem. Suitable for everyday tasks, code, image analysis, and general texts.
Claude: long context and nuanced style
200,000 token context window, nuanced writing style, and deep document analysis. Best for long contracts and complex analysis.
Gemini: Google integration
Works with up-to-date data, Google Docs, Drive. Convenient for multilingual content and Google Workspace users.
Open models: privacy and price
Llama, Mistral, Qwen — for local use, data confidentiality, and reducing API costs. Popular with large companies.
Weak vs strong prompt
Write me a marketing strategy.
I'm developing a three-month Instagram strategy for a local restaurant. Need: audience analysis, weekly post plan, and engagement tactics. Using Claude because I need a long structured document. Write the strategy in modules: 1) audience portrait; 2) content mix; 3) weekly plan; 4) KPIs.
The second prompt accounts for the chosen model's strengths (long structured document). Result — a complete and practical strategy.
Ready prompt template
Copy and adaptI'm performing the task: [task]. For this I need: [key requirements — length, language, accuracy, creativity]. I'm choosing [model name] because [reason]. Leveraging this model's strengths, optimally complete: [specific assignment].
Why it works
GPT-4o — universal, fast, multimodal. Everyday texts, code, image analysis, general tasks. Standard choice for the OpenAI ecosystem.
Claude (Anthropic) — 200,000 token context window, nuanced writing style, document analysis. Best for long contracts, books, and complex analysis.
Gemini (Google) — integration with Google Docs, Drive, and up-to-date data. Convenient for multilingual content and Google Workspace users.
Open models (Llama, Mistral, Qwen) — local use, data privacy, API cost savings. Large companies often choose this path.
Practice
- Choose a task: for example, write a marketing post or business letter.
- Complete it with the same prompt in GPT-4o and Claude.
- Compare results by tone, accuracy, and format.
- Write down which model performed better and why.
Mini-project
Mini-project: model comparison experiment
Choose a real task and test it on at least two different models. Compare results and determine which model suits it better.
Tasks
- Clearly formulate the task and evaluation criteria.
- Complete the task with the same prompt in GPT-4o and Claude.
- Evaluate both results by tone, accuracy, format, and usefulness.
- Explain which model performed better and why.
Deliverables
- 2 results from different models
- comparison table
- final recommendation with justification
Checklist
Common mistakes
- always using the same model without trying others
- assuming a premium model is always better — cheaper models often handle tasks just as well
- fighting only with the prompt without studying the model's strengths
- not considering price-to-quality ratio — you could do 10x more for the same money
Lesson FAQ
Can you get professional results with free models?
Yes, for many tasks. Free versions of Gemini, ChatGPT Free, and Claude.ai Free give good results. Paid models make a bigger difference on long and complex tasks.
Which model works best in English?
All major models — GPT-4o, Claude, and Gemini — work excellently in English since they are primarily trained on English data. English typically produces the highest quality outputs.