AI-900 Practice Test 15 — 15 Questions

Question 1

A data scientist is using Azure Automated Machine Learning to build a binary classification model for a highly imbalanced dataset (95% negative, 5% positive). The data scientist wants AutoML to select the best model based on a metric that is robust to class imbalance. Which primary metric should the data scientist configure in the AutoML settings?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

AUC_weighted. AUC_weighted is the correct primary metric for imbalanced binary classification because it computes the area under the ROC curve for each class and averages them with weight proportional to the class support. This weighting ensures that the metric reflects performance on both the majority (95% negative) and minority (5% positive) classes, making it robust to severe imbalance. Azure Automated Machine Learning uses AUC_weighted as a recommended metric when the dataset is skewed, as it penalizes models that ignore the minority class.

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Accuracy

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F1_score

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Log_loss

Question 2

A logistics company processes packages on an automated conveyor belt. They need to read shipping labels that are often rotated or skewed, and also detect whether a 'FRAGILE' sticker is present on the package. Which combination of Azure Computer Vision capabilities should they use?

Accepted Answer

OCR (Read API) and Object Detection. The scenario requires reading rotated or skewed text from shipping labels (handled by the OCR Read API, which extracts printed and handwritten text from images, even when rotated or skewed) and detecting whether a 'FRAGILE' sticker is present (handled by Object Detection, which identifies and locates specific objects—like stickers—within an image). Option A correctly pairs these two capabilities to meet both requirements.

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Image Classification and OCR (Read API)

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Object Detection and Face Detection

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Image Classification and Face Detection

Question 3

A construction safety team wants to automatically detect whether workers on a job site are wearing hard hats by analyzing images from surveillance cameras. They have a large set of labeled images containing workers wearing hard hats and workers without hard hats. The team needs to train a model that can identify the location of each hard hat in an image. Which Azure Computer Vision service should they use?

Accepted Answer

Custom Vision – Object Detection. Custom Vision – Object Detection is specifically designed to identify and locate multiple objects within an image by drawing bounding boxes around them. The construction safety team needs to detect the location of each hard hat, which requires object detection, not just classification. Custom Vision allows training a model with labeled images that include bounding box annotations for objects like hard hats.

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Computer Vision – Optical Character Recognition (OCR)

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Face API

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Custom Vision – Image Classification

Question 4

A data scientist has trained a binary classification model to detect fraudulent credit card transactions. The dataset contains 99.9% legitimate transactions and only 0.1% fraudulent ones. The model predicts all transactions as legitimate, achieving 99.9% accuracy on the test set. However, the business requires the model to actually catch as many fraudulent transactions as possible. Which metric would best reveal the model's failure to identify fraud?

Accepted Answer

Recall. Recall (also known as sensitivity) measures the proportion of actual positive cases (fraudulent transactions) that were correctly identified by the model. In this scenario, the model predicts all transactions as legitimate, so it correctly identifies 0 out of the 0.1% fraudulent transactions, yielding a recall of 0%. This directly reveals the model's complete failure to catch fraud, despite the high accuracy.

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Accuracy

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Precision

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F1 score

Question 5

An online news platform receives thousands of articles daily. The editors want to automatically identify the most important topics discussed in each article to help with content categorization. Which Azure Text Analytics capability should they use?

Accepted Answer

Key Phrase Extraction. Key Phrase Extraction (B) is the correct Azure Text Analytics capability because it identifies the most important topics and main points discussed in a document by returning a list of key phrases that summarize the core content. For an online news platform needing to automatically detect topics for categorization, this directly extracts the salient subjects from each article, unlike other capabilities that focus on sentiment, named entities, or language identification.

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Sentiment Analysis

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Named Entity Recognition

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Language Detection

Question 6

A data scientist trains a binary classification model to detect fraudulent transactions. The dataset contains only 1% fraudulent cases. The model predicts 'not fraudulent' for all transactions and achieves 99% accuracy. Which metric would best reveal the model's poor performance on fraud detection?

Accepted Answer

Recall. Recall (sensitivity) measures the proportion of actual positive cases (fraudulent transactions) correctly identified by the model. With 1% fraud, a model that predicts 'not fraudulent' for all transactions will have a recall of 0% because it fails to catch any true positives, despite 99% accuracy. This makes recall the best metric to reveal the model's inability to detect fraud.

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Precision

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F1 score

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Accuracy

Question 7

A legal research firm uses Azure OpenAI Service to answer questions about specific case law documents. They want the model to base its answers exclusively on the content of the provided documents, without using any external knowledge from its training. Which approach should they use?

Accepted Answer

Use the 'Azure OpenAI on your data' feature with a 'Search' data source containing the documents. The 'Azure OpenAI on your data' feature with a 'Search' data source allows the model to retrieve and ground its answers exclusively on the content of the provided documents. This approach uses a search index (e.g., Azure Cognitive Search) to fetch relevant document chunks and inject them into the prompt, ensuring the model does not rely on its pre-trained knowledge. It is the only method that enforces strict document-based grounding without external knowledge leakage.

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Increase the 'temperature' parameter to 0.0

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Use the system message to instruct the model to only use provided documents

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Set the 'max_tokens' parameter to a low value

Question 8

A healthcare company develops an AI system to recommend treatment plans. The system sometimes provides recommendations that contradict standard medical guidelines, leading to potential patient harm. Which Microsoft responsible AI principle is most directly violated?

Accepted Answer

Reliability and safety. The system's recommendations contradicting standard medical guidelines and causing potential patient harm directly violates the Reliability and safety principle. This principle requires AI systems to perform consistently, safely, and as intended, especially in high-stakes domains like healthcare where failures can lead to injury or death. The scenario describes a lack of robustness and failure to meet expected safety standards, which is the core concern of this principle.

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Fairness

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Privacy and security

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Inclusiveness

Question 9

A city traffic department wants to use Azure Computer Vision to automatically analyze live video feeds from traffic cameras. They need to detect and locate common objects such as cars, pedestrians, and bicycles in each frame. The department does not have a labeled dataset for custom training. Which prebuilt Azure Computer Vision capability should they use?

Accepted Answer

Object Detection (part of Image Analysis 4.0). The Object Detection capability within Image Analysis 4.0 can detect and locate common objects (e.g., cars, pedestrians, bicycles) in images or video frames without requiring any labeled dataset. It provides bounding box coordinates for each detected object, which directly meets the requirement to 'detect and locate' objects in live traffic camera feeds.

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Image Analysis (descriptive tags and captions)

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Optical Character Recognition (OCR) API

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Custom Vision object detection

Question 10

A developer uses Azure OpenAI Service to generate creative marketing copy. The API costs are based on the total number of tokens processed (input + output). To minimize costs, the developer wants to ensure that the generated text is as brief as possible while still being effective. Which parameter should the developer adjust in the API request?

Accepted Answer

max_tokens. (max_tokens) is correct because this parameter directly controls the maximum number of tokens the model can generate in a single response. By setting a lower max_tokens value, the developer caps the length of the output, which reduces the total tokens processed (input + output) and thus lowers API costs. Other parameters influence the style or diversity of the output but do not directly limit the length of the generated text.

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temperature

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top_p

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frequency_penalty

Question 11

A data scientist is evaluating a binary classification model that predicts whether a transaction is fraudulent. The test set contains 1,000 transactions: 990 legitimate and 10 fraudulent. The model's predictions are shown in the confusion matrix below. Confusion matrix: Predicted Legitimate Predicted Fraudulent Actual Legitimate 942 48 Actual Fraudulent 2 8 Which metric should the data scientist prioritize if the business goal is to minimize the number of fraudulent transactions that are missed (false negatives)?

Accepted Answer

Recall. Recall (sensitivity) measures the proportion of actual positives correctly identified, calculated as TP/(TP+FN). With 2 false negatives (missed fraudulent transactions), recall is 8/(8+2)=0.80. Minimizing missed fraud directly corresponds to maximizing recall, making it the correct priority for this business goal.

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Precision

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Accuracy

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Specificity

Question 12

Which Azure AI service enables you to train a custom image classification model with your own labeled images?

Accepted Answer

Azure AI Custom Vision. Azure AI Custom Vision (option B) is the correct service because it is specifically designed to allow users to upload their own labeled images, train a custom image classification model, and then deploy it via a REST API endpoint. Unlike the pre-built Azure AI Vision service, Custom Vision provides the ability to fine-tune a model on domain-specific visual concepts using transfer learning, making it ideal for bespoke classification tasks.

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Azure AI Vision (pre-built)

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Azure Machine Learning

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Azure AI Face

Question 13

A marketing team uses Azure OpenAI Service to generate product descriptions. They have a base description and want the model to produce multiple variations with different tones, such as formal, playful, and technical, while still being factually accurate. Which parameter should they adjust to control the randomness and diversity of the output?

Accepted Answer

temperature. Temperature controls the randomness of the model's output by scaling the logits before applying the softmax function. A higher temperature (e.g., 0.8) increases diversity and creativity, while a lower temperature (e.g., 0.2) makes the output more deterministic and focused. For generating product descriptions with different tones while maintaining factual accuracy, adjusting temperature is the correct approach.

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max_tokens

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top_p

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frequency_penalty

Question 14

A data scientist trains a binary classification model to detect a rare disease. The dataset contains 99% negative cases and only 1% positive cases. The model predicts all cases as negative, achieving an accuracy of 99% on the test set. However, the business requires the model to identify as many positive cases as possible. Which metric should the data scientist examine to best reveal that the model is failing to identify any positive cases?

Accepted Answer

Recall. Recall (sensitivity) measures the proportion of actual positive cases correctly identified by the model. With all predictions as negative, recall is 0%, directly revealing the model's failure to detect any positive cases despite the high accuracy.

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Precision

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F1 score

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AUC-ROC

Question 15

A company uses Azure OpenAI Service to power a chat-based support assistant. They have extensive knowledge base documents that contain the correct information. The company wants the assistant to answer questions solely based on the provided documents and avoid generating plausible-sounding but incorrect information. Which approach should they implement to minimize the risk of such fabrications?

Accepted Answer

Retrieval Augmented Generation (RAG) — provide relevant document excerpts as context in the prompt. Retrieval Augmented Generation (RAG) is the correct approach because it grounds the model's responses in actual, retrieved document excerpts provided as context in the prompt. This ensures the assistant answers based solely on the supplied knowledge base, directly minimizing the risk of hallucination (plausible-sounding but incorrect information) by constraining the model to the retrieved facts.

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Increase the temperature parameter to 1.0 to force more creative responses

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Fine-tune the model on the knowledge base documents using supervised learning

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Use prompt engineering with a system message that tells the model to never make up facts