The Microsoft Azure AI Fundamentals (AI-900)

Model Explain Ability.

Most businesses run on trust and being able to open the ML “black box” helps build transparency and trust. In heavily regulated industries like healthcare and banking, it is critical to comply with regulations and best practices. One key aspect of this is understanding the relationship between input variables (features) and model output. Knowing both the magnitude and direction of the impact each feature (feature importance) has on the predicted value helps better understand and explain the model. With model explain ability, we enable you to understand feature importance as part of automated ML runs.

In Azure OpenAI Service, fine-tuning refers to the process of uploading your own labeled dataset to customize or adapt a pretrained model (such as GPT-3.5 or Curie) for a specific use case. According to the Microsoft Learn documentation and AI-900 official study guide, fine-tuning allows organizations to improve a model’s performance on domain-specific tasks or to align responses with brand tone and context.

Fine-tuning differs from simple prompting because it requires providing structured training data (usually in JSONL format) that contains pairs of input prompts and ideal completions. The model uses this data to adjust its internal weights, thereby “learning” your organization’s language patterns, terminology, or industry context.

Option review:

A. Completion: Refers to the text generated by a model in response to a prompt. It’s the output, not the customization process.

B. Grounding: Integrates external, up-to-date data sources (like search results or databases) during inference but doesn’t alter the model’s parameters.

C. Fine-tuning: ✅ Correct — this is the process of uploading and training with your own data.

D. Prompt engineering: Involves designing effective prompts but does not change the underlying model.

Thus, fine-tuning is the term used for customizing an Azure OpenAI model using your own uploaded data.

The correct answers are A. Create images and D. Modify images.

The Azure OpenAI DALL-E model is a text-to-image generative AI model that can create original images and modify existing ones based on text prompts. According to Microsoft Learn and Azure OpenAI documentation, DALL-E interprets natural language descriptions to produce unique and creative visual content, making it useful for design, illustration, marketing, and educational applications.

Create images (A) – DALL-E can generate new images entirely from textual input. For example, the prompt “a futuristic city skyline at sunrise” would result in a custom-generated artwork that visually represents that description.

Modify images (D) – DALL-E also supports inpainting and outpainting, allowing users to edit or expand existing images. You can replace parts of an image (for example, changing a background or object) or add new elements consistent with the visual style of the original.

The remaining options are incorrect:

B. OCR is performed by Azure AI Vision, not DALL-E.

C. Detect objects in images is also an Azure AI Vision (Image Analysis) feature.

E. Generate captions for images is handled by Azure AI Vision, not DALL-E, since DALL-E generates—not interprets—visuals.

The correct answer is B. Face because the Azure Face service, part of Azure Cognitive Services, provides capabilities for detecting, recognizing, and analyzing human faces in images. According to the Microsoft Azure AI Fundamentals (AI-900) official study guide and Microsoft Learn module “Explore computer vision”, the Face service can automatically detect faces, determine attributes such as age, gender, emotion, and identify or verify individuals based on facial features.

In this scenario, the goal is to build an image tagging solution that automatically tags images of friends on social media. This requires the ability to recognize and match faces of known individuals, which is a key feature of the Face API. The API uses facial recognition technology to create face IDs for detected faces and can compare new faces against stored face data to identify known individuals. Microsoft Learn notes: “The Face service can detect, recognize, and identify people in images, enabling automated tagging or authentication scenarios.”

Other options explained:

A. Computer Vision identifies objects, landmarks, and general content but does not specialize in identifying individual people.

C. Text Analytics analyzes textual data for sentiment, key phrases, or entities, not image data.

D. Form Recognizer extracts structured data from forms or receipts, unrelated to face detection.

Thus, for automatically tagging people in photos, Azure Face is the correct and most suitable service.

https://docs.microsoft.com/en-us/azure/machine-learning/algorithm-module-reference/split-data

The correct answer is B. Randomly split the data into rows for training and rows for evaluation.

According to the Microsoft Azure AI Fundamentals (AI-900) official study guide and the Microsoft Learn module “Describe fundamental principles of machine learning on Azure”, the process of developing a machine learning model involves dividing the available dataset into two or more parts—commonly training data and evaluation (or testing) data. The goal is to ensure that the model can learn patterns from one subset of the data (training set) and then be objectively tested on unseen data (evaluation set) to measure how well it generalizes to new situations.

The training dataset contains both features (the measurable inputs) and labels (the target outputs). The model learns from the patterns and relationships between these features and labels. The evaluation dataset also contains features and labels, but it is kept separate during the training phase. Once the model has been trained, it is tested on this unseen evaluation data to calculate metrics like accuracy, precision, recall, or F1 score.

Microsoft emphasizes that the data split should be random and based on rows, not columns. Each row represents a complete observation (for example, one customer record, one transaction, or one image). Randomly splitting ensures that both subsets represent the same distribution of data, avoiding bias. Splitting by columns would separate features themselves, which would make the model training invalid.

The AI-900 materials often illustrate this using Azure Machine Learning’s data preparation workflow, where data is randomly divided (commonly 70% for training and 30% for testing). This ensures the model learns from diverse examples and is fairly evaluated.

Therefore, the verified and correct approach, as per Microsoft’s official guidance, is B. Randomly split the data into rows for training and rows for evaluation.

In Azure Machine Learning designer, a low-code drag-and-drop interface, users can visually build machine learning workflows. According to the AI-900 study guide and Microsoft Learn module “Create and publish models with Azure Machine Learning designer”, two key components that can be dragged onto the designer canvas are datasets and modules.

Datasets (A): These are collections of data that serve as the input for training or evaluating models. They can be registered in the workspace and then dragged onto the canvas for use in transformations or model training.

Modules (D): These are prebuilt processing and modeling components that perform operations such as data cleaning, feature engineering, model training, and evaluation. Examples include “Split Data,” “Train Model,” and “Evaluate Model.”

Compute (B) and Pipeline (C) are not drag-and-drop items within the designer. Compute targets are infrastructure resources used to run the pipeline, while a pipeline represents the overall workflow, not a component that can be added like a dataset or module.

Hence, the correct answers are A. Dataset and D. Module.

According to the Microsoft Azure AI Fundamentals (AI-900) Official Study Guide and the Microsoft Learn module “Explore fundamental principles of machine learning,” anomaly detection is a machine learning workload used to identify data points or patterns that deviate significantly from expected behavior.

In this scenario, the IoT device monitors engine temperature and generates alerts when the readings deviate from normal operating ranges. This directly matches the definition of anomaly detection, where the AI system learns what “normal” looks like and identifies outliers or abnormal conditions that may indicate potential issues.

Common real-world uses of anomaly detection include:

Detecting equipment malfunctions or overheating in IoT systems.

Identifying fraudulent transactions in finance.

Detecting unusual spikes or drops in system metrics (e.g., temperature, traffic, or pressure).

Other options are incorrect:

A. NLP (Natural Language Processing): Focuses on understanding and interpreting human language, not sensor data.

B. Computer Vision: Involves analyzing images or videos, which is unrelated to temperature data.

D. Knowledge Mining: Refers to extracting information from large document stores, not identifying abnormal readings.

According to the Microsoft Azure AI Fundamentals (AI-900) Official Study Guide and the Microsoft Learn module “Explore Azure Machine Learning”, when you publish an inference pipeline (a deployed web service for real-time predictions) using Azure Machine Learning designer, you make the model accessible as a RESTful endpoint. Consumers—such as applications, scripts, or services—interact with this endpoint to submit data and receive predictions.

To securely access this deployed pipeline, two critical parameters are required:

REST endpoint (Option D):The REST endpoint is a URL automatically generated when the inference pipeline is deployed. It defines the network location where clients send HTTP POST requests containing input data (usually in JSON format). The endpoint routes these requests to the deployed model, which processes the data and returns prediction results. The REST endpoint acts as the primary access point for consuming the model’s inferencing capability programmatically.

Authentication key (Option C):The authentication key (or API key) is a security token provided by Azure to ensure that only authorized users or systems can access the endpoint. When invoking the REST service, the key must be included in the request header (typically as the value of the Authorization header). This mechanism enforces secure, authenticated access to the deployed model.

The other options are incorrect:

A. The model name is not required to consume the endpoint; it is used internally within the workspace.

B. The training endpoint is used for training pipelines, not for inference.

Therefore, according to Microsoft’s official AI-900 learning objectives and Azure Machine Learning documentation, when consuming a published inference pipeline, you must use both the REST endpoint (D) and the authentication key (C). These parameters ensure secure, controlled, and programmatic access to the deployed AI model for real-time predictions.

For an app that helps employees write emails and reports based on user prompts, you need a text generation model capable of understanding natural language instructions and producing coherent, contextually appropriate output. Azure OpenAI GPT models—available through Azure AI Foundry (formerly Azure OpenAI Studio)—are specifically designed for such generative tasks.

By integrating GPT-3.5 or GPT-4, the app can analyze prompts like “Write a professional email to a client about project updates” and automatically generate polished text in seconds.

The other options do not fit:

A. Azure AI Speech: Converts spoken language to text or text to speech; not suitable for generating written content.

C. Azure AI Vision: Processes and analyzes images or video content.

D. Azure Machine Learning Studio: Used for training, testing, and deploying custom ML models, not directly for content generation.

Therefore, to create a writing-assistance app for emails and reports, the correct solution is B. Azure OpenAI in Foundry Models using GPT-based language generation.