Augmented Language Models: a Survey

A important survey for ALM from Yann LeCunn

This paper — Augmented Language Models: a Survey — studies how to extend language models beyond pure text prediction into systems that think and interact with the world.

Paper: https://arxiv.org/abs/2302.07842

The authors propose that modern LLM systems are evolving toward a new paradigm:

Not just predicting text, but solving tasks.

They call these systems Augmented Language Models (ALMs) — language models enhanced with reasoning abilities and external tool usage.

The survey organizes almost all modern LLM agent research into two core axes:

  1. Reasoning (thinking before answering)
  2. Acting / Tools (interacting with the environment)

Why Augmentation Is Needed

Traditional LLMs optimize next-token prediction:

P(xt∣x<t)P(x_t | x_{<t})P(xt​∣x<t​)

This makes them powerful at language, but weak at:

  • multi-step planning
  • long horizon tasks
  • factual grounding
  • interacting with real systems

ALMs overcome this by integrating non-parametric modules (search, calculators, APIs, interpreters) while still keeping the language modeling objective unchanged.

In other words:

The model remains a language model — but operates as a cognitive system.

Reasoning

Definition

Give more computation steps to the model before yielding the answer to a prompt.

More precisely:

Decompose complex tasks into simpler subtasks with a hierarchical structure.

The Key Idea: Thinking Improves Accuracy

Instead of answering directly:

Standard LM

Q: 17×24?
A: 408 (sometimes wrong)

Reasoning LM

17×24
= 17×(20+4)
= 340 + 68
= 408

By generating intermediate steps, the model converts a single difficult prediction into many easy predictions.

This dramatically improves performance on math, logic, and planning tasks.


Methods Covered in the Survey

Chain-of-Thought Prompting

Models explicitly generate intermediate reasoning steps before the answer.

This helps logical tasks because the model externalizes hidden computation.

Recursive Decomposition

Break a problem into smaller subproblems and solve sequentially.

Self-Improvement / Reflection

Models critique or revise earlier steps.


Key Insight

Reasoning changes the role of inference:

Inference becomes computation.

Instead of scaling model size, we scale thinking time.

Tool & Acting

Definition

Gather external information, or affect the virtual/physical world — importantly observable by the model afterward.

The model interacts with modules such as:

  • search engines
  • code interpreters
  • calculators
  • databases
  • APIs

This is not just retrieval — it is closed-loop interaction.

The survey defines tool use as calling external modules to extend capability beyond the training data.


The Key Idea: Models Should Not Memorize the World

A pure LLM must store knowledge internally.

An ALM instead queries reality:

User: What's the weather in Tokyo?
LM → API → receives data → answers

This turns the model from:

knowledge container → knowledge interface

Acting: LLM as an Agent

When tools affect the environment, the model becomes an agent.

Example loop:

Observe → Think → Act → Observe → Think → Act

This paradigm appears in systems like ReAct, where reasoning traces guide action planning and environment interaction.


Combining Reasoning and Acting

The most powerful systems combine both.

CapabilityReasoningActing
Math✓
Planning✓✓
Web navigation✓
Autonomous agents✓✓

Reasoning decides what to do
Acting executes how to do it

The New View of Language Models

The survey suggests a shift in perspective:

Old paradigm:

LLM = text generator

New paradigm:

LLM = controller of computation and interaction

Augmented Language Models remain trained with next-token prediction, but learn to reason, call tools, and act through prompting or demonstrations.


Why This Paper Matters (Looking Forward)

This survey predicted nearly all modern agent research:

  • tool-calling LLMs
  • RAG systems
  • code interpreter models
  • planning agents
  • web agents
  • reasoning models

Today’s AI assistants are essentially ALMs.


Final Takeaway

The paper’s core message:

Intelligence does not come from the model alone —
it comes from the model orchestrating computation.

Reasoning gives models internal cognition.
Acting gives models external embodiment.

Together they turn a language model into a general problem-solving system.


Reference

Mialon et al., Augmented Language Models: a Survey, 2023
https://arxiv.org/abs/2302.07842