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NVIDIANVIDIA-Certified Professional: Agentic AI2026-100 Prerequisites

Choose models by task and training

Completed by the knowledge check

Learning objective

Distinguish foundation, instruction-tuned, and reasoning LLMs.

Core idea

Separate what a model learned during training from how you ask it to behave during inference. A foundation large language model (LLM) provides broadly reusable language capabilities. Instruction tuning adapts a pretrained model to respond to instructions. Reasoning models support additional inference-time reasoning before producing an answer.

These categories overlap: an instruction-tuned reasoning model still builds on a pretrained foundation. They describe training and behavior, rather than three interchangeable deployment products. For an agent, the useful question is which behavior satisfies the task within its latency and quality constraints.

How it works

A base language model learns patterns from a training corpus and predicts continuations. That capability provides a starting point for adaptation; it does not establish that a checkpoint follows a particular assistant’s instruction format reliably.

Supervised fine-tuning (SFT) changes model parameters using examples of inputs and desired outputs. Instruction tuning teaches the model to follow the supplied instructions and respond in the demonstrated style. Writing a system prompt at request time supplies input; it does not perform SFT or change the weights.

NIM’s NVIDIA-Nemotron-3.5-Super-VL-120B-A12B deployment enables reasoning by default. Set chat_template_kwargs.enable_thinking: false to disable it per request, or use reasoning_effort: low and medium select shorter reasoning; high selects full reasoning. Reasoning tokens count toward max_tokens, so leave room for the final answer. Do not use this model’s thinking_token_budget to cap reasoning: reaching it leaves content empty; use the documented effort or thinking controls instead.

Response fields also depend on the model: Nemotron returns reasoning in choices[].message.reasoning, while NIM’s GLM-5.2 page documents choices[].message.reasoning_content. Neither the control nor the response field is universal.

You must budget generation for reasoning and the final answer. More generated reasoning consumes inference work and time; evaluate whether the resulting task improvement earns that cost. See 3.4.2 for model size and reasoning-budget selection, and 5.2.1 for reasoning modes within token budgets.

Key distinctions and trade-offs

Training versus prompting: Fine-tuning changes weights. A prompt changes the input to an inference request. A strong instruction prompt does not turn a base checkpoint into an instruction-tuned one.

Reasoning versus action: Reasoning produces model output; a tool executor changes or queries the environment. A reasoning-capable model does not, by that label alone, implement an agent loop. See 0.4.

Capability versus suitability: A model that solves difficult planning questions can still be a poor choice for a brief extraction task with a tight response target. Compare completed task quality and latency, rather than selecting by the category name.

Architecture / decision scenario

A manufacturer’s employee assistant must classify maintenance tickets within a two-second response target. In an illustrative internal test, an instruction-tuned candidate achieves 96% acceptance at 1.2 seconds; a reasoning-enabled candidate achieves 97% at 4.8 seconds. A base checkpoint requires additional adaptation before it follows the ticket format consistently.

The tempting proposal is reasoning for every request because its acceptance rate is higher, but that path misses the target. The assistant owner also tests a shared reasoning-capable deployment with enable_thinking: false for classification and thinking enabled for investigations. This leaves one deployment to operate, but its classification latency and accuracy still need measurement. A smaller dedicated instruction model adds a deployment to operate and must earn that cost against the shared option’s measured results. The owner keeps classification on the dedicated candidate unless the shared option meets two seconds and at least 96% acceptance with thinking off. The model team owns base-model adaptation; changing a prompt is a different intervention.

Common exam traps

  • Treating foundation, instruction-tuned, and reasoning as mutually exclusive architectures.
  • Calling a request-time prompt a weight update.
  • Assuming longer reasoning guarantees a better answer or successful tool execution.
  • Applying one model’s thinking control to every NIM deployment.

What to remember

Identify the training stage, the documented inference behavior, and the task’s operating constraints separately. Choose instruction following or reasoning from measured task results, and verify the model-specific request interface.

Knowledge check

References