ChatGPT, Gemini, and Claude each offer four to five different models and reasoning levels today, and most users simply always choose the default setting. That comes at the expense of either quality or time. This guide uses three simple questions to help you determine which model is right for your needs, featuring a decision tree, a comprehensive model matrix, and over 20 sample prompts.
Just two years ago, there was one model per provider. Today, the reality is different: With ChatGPT, you select GPT-5.5 and one of three intelligence levels (Immediate, Medium, High). With Gemini, you can choose from 3.1 Flash-Lite, 3.5 Flash, and 3.1 Pro, each of which can be combined with the Standard and Extended Thinking Levels. Claude’s lineup ranges from Haiku 4.5 to Sonnet 5 and Opus 4.8, all the way up to the top-of-the-line model, Fable 5. In addition, there are image models such as GPT Image 2 and Nano Banana and the question of which provider can actually create ready-made documents such as Word, PowerPoint, or Google Docs.
I know this from experience gained in hundreds of workshops with Swiss banks, insurance companies, and SMEs: Some of them use the slowest decision-making process for even the smallest tasks and wait minutes for a simple email. Others let the fastest model handle complex contract analyses and are surprised by the superficial results. Both can be avoided if you can answer three simple questions.
The AI Model Guide is a 6-page PDF by Dr. Sophie Hundertmark that helps users of ChatGPT, Gemini, and Claude determine which AI model is best suited for which task by answering three questions. At its core is a decision tree with three entry points—”quick question,” “task,” and “image”—three levels of complexity, and a trade-off between speed and depth of detail. In addition, there is a model matrix featuring all 12 current model variants from the three providers, over 20 sample prompts for easy mapping, and custom tables for image generation and document creation. The guide costs CHF 15 and is available for immediate download after purchase.
Specifically, the guide contains:
For professionals who already use ChatGPT, Gemini, or Claude and feel like they’re not getting the most out of them: You’ll learn a clear rule for when to use the “thinking” model and when the “fast” model is the better choice—saving you time and quota every day.
For teams and small and medium-sized businesses (SMEs) looking to standardize the use of AI within their organizations: This guide serves as a common standard. Print out the decision tree, share the PDF with your team, and everyone will be on the same page when it comes to choosing a model.
For trainers, instructors, and AI managers who help others get started: The three levels of complexity and the sample prompts are intentionally designed so that they can be used directly in training sessions and onboarding programs.
The guide costs CHF 15 as a one-time payment. There is no subscription and no recurring fees. After purchase, the PDF will be available for immediate download.
This guide covers the three most widely used AI assistants: ChatGPT from OpenAI (GPT-5.5 with the intelligence levels Immediate, Medium, and High), Google Gemini (3.1 Flash-Lite, 3.5 Flash and 3.1 Pro with the thinking levels Standard and Extended) and Claude by Anthropic (Haiku 4.5, Sonnet 5, Opus 4.8, and Fable 5). He also discusses the image models GPT Image 2 and Nano Banana, as well as document generation across all three providers.
The guide is current as of July 2026 and shows the sample menus exactly as they currently appear in the apps. Since the model landscape is constantly changing, the date of the last update is noted on each page. The underlying logic—categorizing issues, determining complexity, and balancing speed against depth—remains valid even with new versions of the model.
No. This guide is intentionally written for users, not for developers. If you’ve ever used ChatGPT, Gemini, or Claude, you can start using the decision tree right away. The sample prompts will help you classify your issue at the correct level without using technical terms.
This purchase is for personal use. For team and enterprise licenses or accompanying training, please contact sophie@hundertmark.ch directly—we offer workshop formats tailored to small and medium-sized businesses.
Payment is processed through a secure payment system (credit card or TWINT). Immediately after payment, you’ll receive the download link on the confirmation page and via email as well. The PDF can be opened and printed on any device.
