AI-900 Practice Exam 2 — 20 Questions

Question 1

A legal firm needs to automatically produce a short summary of each lengthy court ruling, highlighting the most important sentences. Which Azure AI Language feature should they use?

Accepted Answer

Extractive summarization. Extractive summarization (Option C) is the correct Azure AI Language feature because it identifies and extracts the most important sentences from a document to produce a concise summary. This directly matches the legal firm's requirement to automatically generate a short summary of lengthy court rulings by highlighting key sentences, without generating new text.

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Key phrase extraction

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Named entity recognition

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Sentiment analysis

Question 2

What is 'token pricing' in Azure OpenAI and what counts as a token?

Accepted Answer

A billing unit roughly equal to ¾ of an English word, counting both input and output. Azure OpenAI uses token-based pricing, where a token is a billing unit that represents roughly 0.75 of an English word. Both input (prompt) and output (completion) text are counted toward the total token usage, and the cost is calculated based on the total number of tokens consumed per API call.

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A billing unit roughly equal to one character in the input or output text

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A subscription-based pricing model where a fixed number of API calls are included monthly

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Authentication tokens required to secure API calls to Azure OpenAI

Question 3

A museum wants to create an interactive exhibit where visitors can type a description of a fictional creature, such as 'a fire-breathing dragon with emerald scales and golden wings,' and the system generates an image of that creature in real time. The museum must ensure that the generated images are safe and appropriate for all ages, including children. Which Azure service should they use, and which safety feature should they configure?

Accepted Answer

Azure OpenAI Service with the DALL-E 2 model and content filtering enabled. Azure OpenAI Service with DALL-E 2 is specifically designed for generating images from text descriptions, and enabling content filtering ensures the output is safe for all ages, including children. This combination directly meets the museum's requirement for real-time, safe image generation from textual prompts.

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Azure Cognitive Services Computer Vision with custom vision image generation

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Azure OpenAI Service with the GPT-4 model and content filtering enabled

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Azure OpenAI Service with the DALL-E 2 model without content filtering

Question 4

A developer uses Azure OpenAI Service to generate product descriptions. Each description must be concise and not exceed 50 words. Which parameter should the developer set in the API request to control the output length?

Accepted Answer

max_tokens. The `max_tokens` parameter in the Azure OpenAI API directly controls the maximum number of tokens (words or subwords) in the generated output. By setting `max_tokens` to a value that corresponds to 50 words, the developer ensures the model stops generating once the limit is reached, producing concise descriptions.

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Temperature

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top_p

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frequency_penalty

Question 5

What is named entity recognition (NER) and provide an example of its output?

Accepted Answer

NER identifies and categorizes named entities like people, organizations, locations, and dates in text. Named entity recognition (NER) is a natural language processing (NLP) capability that identifies and classifies key elements in text into predefined categories such as person names, organizations, locations, dates, and quantities. Option B correctly describes this function, and its output typically includes the extracted entity along with its category label, for example, {'entity': 'Microsoft', 'category': 'Organization'}.

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NER identifies grammatical parts of speech like nouns and verbs

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NER generates new names for products based on brand guidelines

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NER converts names into anonymous placeholders for privacy

Question 6

What is 'model interpretability' and which Azure tool helps with it?

Accepted Answer

Understanding why a model makes specific predictions by identifying influential features — supported by Azure ML's Responsible AI dashboard. Model interpretability refers to the ability to understand and explain why a machine learning model makes specific predictions, typically by identifying which input features most influenced the output. Azure Machine Learning's Responsible AI dashboard directly supports this through built-in interpretability components like feature importance plots and error analysis, enabling developers to debug models and build trust. Option B correctly pairs the definition with the specific Azure tool that implements it.

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Understanding what programming language a model was written in

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Translating model documentation into multiple languages

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Monitoring how quickly a model responds to prediction requests

Question 7

What is the Azure AI Vision background removal feature used for?

Accepted Answer

Automatically separating foreground subjects from the background in images. Azure AI Vision background removal is designed to automatically separate foreground subjects from the background in images, producing a mask or a cut-out of the primary object. This feature uses deep learning models to identify and isolate the main subject, enabling further processing like compositing or analysis without the background.

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Blurring the background to create depth of field effects

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Identifying what type of background (indoor/outdoor) is in an image

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Replacing backgrounds in video calls

Question 8

What is 'sentiment analysis' at the opinion mining level vs. document level in Azure AI Language?

Accepted Answer

Document-level assigns one overall sentiment; opinion mining extracts per-aspect sentiments. In Azure AI Language, document-level sentiment analysis assigns a single overall sentiment (positive, negative, neutral, or mixed) to the entire document, while opinion mining (a feature of aspect-based sentiment analysis) extracts sentiments for specific aspects or targets within the text, such as 'service' or 'food' in a restaurant review. This allows for granular, per-aspect sentiment detection rather than a single aggregate score.

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Document-level is more accurate; opinion mining is a faster but less precise approximation

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Opinion mining works only on social media posts; document-level works on all text types

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Document-level sentiment requires training data; opinion mining is pre-built

Question 9

What is 'Azure AI Vision's image vectorisation' and how does it enable image search?

Accepted Answer

Converting images to semantic embedding vectors for similarity-based search and retrieval. Azure AI Vision's image vectorisation converts images into semantic embedding vectors—numerical representations that capture the visual content and meaning of an image. These vectors enable similarity-based search by allowing the system to compare the vector of a query image against a database of pre-computed image vectors, returning the most visually or semantically similar results.

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Converting image files to a vectorised (lossless) format like SVG for web use

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Drawing vector graphics from a description of an image's contents

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Optimising image file size by converting to the most efficient vector format

Question 10

A data scientist trains a regression model to predict energy consumption for a smart building. The model achieves very low error on the training data but performs significantly worse on a held-out validation set. Which technique would most directly address this problem?

Accepted Answer

Regularization. The model's low training error but high validation error indicates overfitting, where the model has memorized the training data rather than learning generalizable patterns. Regularization (e.g., L1 or L2) directly penalizes large coefficients, reducing model complexity and improving generalization to unseen data.

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Feature engineering

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Cross-validation

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Hyperparameter tuning

Question 11

What does it mean for an ML model to 'generalize'?

Accepted Answer

The model's ability to perform well on new, unseen data by learning underlying patterns rather than memorizing training examples. Generalization in machine learning refers to the model's ability to accurately predict outcomes on new, unseen data by learning the true underlying patterns from the training data, rather than simply memorizing the training examples (overfitting). A model that generalizes well will maintain high performance on a validation or test dataset that was not used during training, which is a core requirement for deploying reliable ML solutions in Azure Machine Learning.

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Making the model work for all programming languages and platforms

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Making the model output descriptions in plain language for non-technical users

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Training a model that works for all possible tasks without specialization

Question 12

What is 'cross-validation' and when should it be used in machine learning?

Accepted Answer

Dividing data into k folds and training k times to get a more reliable performance estimate. Cross-validation is a resampling technique used to evaluate machine learning models by partitioning the original dataset into k equal-sized folds. The model is trained on k-1 folds and validated on the remaining fold, repeating this process k times so each fold serves as the validation set once. This provides a more robust and less biased estimate of model performance compared to a single train-test split, especially when data is limited.

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Validating that a model works correctly across different Azure regions

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Comparing two different models' predictions on the same test set

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Checking whether training labels are consistent across different human annotators

Question 13

What is reinforcement learning?

Accepted Answer

Training an agent through rewards and penalties in an interactive environment. Reinforcement learning is a machine learning paradigm where an agent learns to make decisions by interacting with an environment, receiving rewards for desirable actions and penalties for undesirable ones. This trial-and-error process allows the agent to develop an optimal policy over time, distinct from supervised or unsupervised learning. In Azure, this is exemplified by services like Azure Machine Learning's reinforcement learning capabilities or integration with platforms like Ray RLlib.

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A type of supervised learning that uses labeled training data

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A clustering technique that groups similar data automatically

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Using previously trained models on new tasks

Question 14

What is 'celebrity recognition' in Azure AI Vision and what are its responsible AI limitations?

Accepted Answer

Recognising well-known public figures in images, with responsible AI access restrictions. Celebrity recognition in Azure AI Vision is a specialized feature that identifies well-known public figures (e.g., actors, politicians, athletes) in images. It is not a general-purpose facial identification service; instead, it relies on a curated dataset of public figures and is subject to responsible AI access restrictions, including limited availability and usage policies to prevent misuse.

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Identifying any person by their face in a photograph using a global identity database

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Automatically tagging images with the names of all people photographed at an event

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A feature available to all Azure customers for identifying any person in any image

Question 15

What is 'conversation summarisation' in Azure AI Language?

Accepted Answer

Generating concise summaries of dialogues capturing key points, decisions, and action items. Conversation summarization in Azure AI Language is a prebuilt feature that uses extractive and abstractive summarization techniques to generate concise summaries of dialogues, capturing key points, decisions, and action items. It is designed specifically for multi-turn conversations (e.g., customer service chats, meeting transcripts) and outputs a structured summary, not just a count of messages.

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Summarising how many messages were exchanged in a conversation

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A tool for moderators to summarise flagged content for compliance review

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Automatically creating FAQ articles from the most common chatbot conversations

Question 16

A data scientist is building a machine learning model to predict whether a credit card transaction is fraudulent or legitimate. The dataset contains 100,000 historical transactions, each labeled as 'fraudulent' or 'legitimate'. Which type of machine learning task should the data scientist use in Azure Machine Learning?

Accepted Answer

Binary classification. Binary classification is the correct choice because the prediction task involves distinguishing between exactly two mutually exclusive classes: 'fraudulent' and 'legitimate'. In Azure Machine Learning, binary classification algorithms (e.g., Two-Class Logistic Regression, Two-Class Boosted Decision Tree) are designed to output a probability score for one of two labels, making them ideal for this fraud detection scenario.

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Regression

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Multi-class classification

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Clustering

Question 17

What does the Azure AI Vision 'Image Analysis' capability return when analyzing an image?

Accepted Answer

Descriptions, objects, tags, and other semantic information about the image content. Azure AI Vision's Image Analysis capability uses pre-trained deep learning models to extract rich semantic information from images, including human-readable descriptions, a list of detected objects with bounding boxes, and a set of relevant tags. This goes far beyond basic metadata, making option B correct because it accurately captures the breadth of semantic outputs the service provides.

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Only the file size and dimensions of the image

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Only a single category label for the entire image

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A 3D point cloud of the scene

Question 18

A retail company wants to use security cameras to analyze customer flow. They need to detect when a person enters a specific store zone, count how many people are in that zone at any given time, and track the direction each person moves within the zone. Which Azure Computer Vision capability should they use?

Accepted Answer

Spatial Analysis. Spatial Analysis is the correct Azure Computer Vision capability because it is specifically designed to analyze video feeds from cameras to detect people, count them in defined zones, and track their movement direction. Unlike general object detection, Spatial Analysis provides the specialized functions for zone occupancy and person trajectory tracking required by the retail scenario.

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Object detection

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Optical Character Recognition (OCR)

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Semantic segmentation

Question 19

What is the difference between entities and intents in conversational language understanding?

Accepted Answer

Intents represent the user's goal; entities are the specific pieces of information within the utterance. In conversational language understanding (CLU), intents represent the user's overall goal or desired action (e.g., 'BookFlight'), while entities are specific data points extracted from the utterance that provide context for that intent (e.g., 'New York' as a destination). This distinction is fundamental to natural language processing (NLP) on Azure, where intents map to actions and entities provide the parameters needed to fulfill those actions.

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Intents are for text; entities are for speech recognition

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Intents are predefined answers; entities are user questions

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They are the same concept with different names for clarity

Question 20

What is 'feature importance' in Azure Machine Learning and how is it used?

Accepted Answer

Quantifying how much each input variable contributes to a model's predictions. Feature importance is a technique in Azure Machine Learning that quantifies the contribution of each input variable (feature) to a model's predictions. It is used to interpret model behavior, identify the most influential features, and validate that the model aligns with domain knowledge. This is critical for debugging, improving model performance, and ensuring regulatory compliance.

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Ranking which ML project features (notebooks, experiments, pipelines) are most used by the team

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Determining which model features (capabilities) are included in each Azure ML pricing tier

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The priority order in which data preprocessing steps are applied before training