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AI0-001 Implementing AI Solutions Practice Question

A team fine-tunes a 7B parameter LLM using LoRA on a custom instruction dataset. After training, they observe that the model's outputs are only marginally different from the base model. Which is the MOST likely cause?

⚠ Common exam trap

AI0-001 often tests the misconception that a low LoRA rank is sufficient for any task, confusing parameter efficiency with learning capacity, and candidates may incorrectly attribute marginal output differences to dataset size or learning rate instead of the rank's direct impact on adapter expressiveness.

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

✓

The LoRA rank was set too low (e.g., r=1), limiting the adapter's capacity to learn the task

LoRA (Low-Rank Adaptation) injects trainable low-rank matrices into the model's attention layers. The rank r determines the dimension of these matrices and thus the adapter's capacity to capture task-specific patterns. With r=1, the update matrices are extremely low-rank, severely restricting the number of parameters that can be tuned and limiting the model's ability to learn complex instruction-following behavior. As a result, the fine-tuned model's outputs remain very close to the base model, as observed.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

  • ✗

    The dataset contained too many examples, overfitting the adapter

    Why it's wrong here

    Overfitting produces outputs that memorise training examples and degrade on unseen prompts, not outputs resembling the base model. Excess data alone does not neutralise an adapter; the marginal difference points to under-training or a low LoRA rank, so this cause is inconsistent with the symptom.

  • ✗

    The base model was too small to benefit from fine-tuning

    Why it's wrong here

    A 7B model fine-tunes effectively with LoRA; parameter count is not the limiting factor here. The tempting reasoning is that larger models capture more, but the actual cause is usually insufficient training steps or a low LoRA rank, leaving adapter weights barely changed from initialisation.

  • ✓

    The LoRA rank was set too low (e.g., r=1), limiting the adapter's capacity to learn the task

    Why this is correct

    LoRA rank controls the dimensionality of the low-rank update matrices, so r=1 gives the adapter minimal capacity to capture task-specific patterns. The adapter therefore learns too little, leaving outputs close to the frozen base model.

  • ✗

    The learning rate was too high, causing the model to diverge

    Why it's wrong here

    A high learning rate causes loss divergence, visible as erratic or degraded output, not output that closely resembles the base model. Divergence would corrupt the adapter rather than leave it near its initialised state, so this does not explain the marginal behavioural shift observed after training.

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JA

Written and reviewed by Johnson Ajibi, MSc IT Security

Senior Network & Security Engineer · founder of Courseiva

Last reviewed September 2026 · checked against the official CompTIA exam blueprint

This AI0-001 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the AI0-001 exam.