Advanced level · Module 1: Designing AI Systems · Lesson 3 of 4
Choosing Models
Choose models by task quality, cost, speed, data handling and availability.
In this lesson you will
- Compare hosted and open models
- Select models against explicit criteria
Key concepts
hosted vs open-weight modelsmodel size and qualitydata handling and locationvendor dependence
The lesson
Hosted models are accessed through providers' APIs: strong and easy to start with, but data leaves your systems and costs are paid in foreign currency. Open-weight models can be run on your own hardware, keeping data local, but need technical capacity.
Choose against explicit criteria measured on your own evaluation set: quality, cost per task, speed, languages supported, data policies and availability.
Avoid lock-in: keep prompts and evaluation sets provider-neutral and design so models can be swapped.
Step by step
- List candidate hosted and open models.
- Run the evaluation set on two or three.
- Compare against the criteria.
- Choose and document a fallback.
Practice activity
Select the capstone model with evidence and a fallback option.
Expected result: A documented choice with evaluation results and a fallback.
Check your understanding
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What is a key advantage of open-weight models?
Show answer
They can run on your own hardware, keeping data local.
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How can lock-in to one provider be reduced?
Show answer
Keep prompts and evaluations provider-neutral and design for swappable models.
Taught live by an instructor — online or in person. Free course lessons are for self-study and do not lead to a certificate — see registration options.