by Amit Shekhar · 12 May 2026
Large Reasoning Models (LRMs)
Large Reasoning Models (LRMs), how they are different from standard Large Language Models, how they think before they answer, how they are trained, and when we must use them.
Read on Outcome School ↗then come back to lock it in
Before you read, guessWhat is the long internal scratchpad of tokens produced before the final answer?
Ten seconds, a guess, then read — a wrong guess still makes the answer stick.
What this article covers
- The Big Picture
- What is a Large Reasoning Model (LRM)?
- LLM vs LRM
- How does an LRM actually think?
- Test-time compute: thinking longer makes them smarter
- How are LRMs trained?
- Input and Output: training phase vs prediction phase
- When to use an LRM, and when to use a regular LLM
- Popular LRMs we should know
- Common Mistakes when using LRMs
The article lives on outcomeschool.com. Read it there, then come back: the tutor in the margin has read it and will answer questions, and the questions below check what stayed.