Applied Machine Learning Research Lab

Information Retrieval

Teaching / CSCI 4141

Summer 2026 · Dalhousie University

Information Retrieval

How does a system find the right document, image, product, or answer? This course builds search from first principles, then follows the same ideas into vector databases, recommender systems, retrieval-augmented generation, and agent memory.

12 weeks4 implementation assignmentsSearch to agentic retrieval

What you will learn

01Represent information

Turn text, images, queries, and users into representations that a retrieval system can compare.

02Rank and evaluate

Build ranking functions and select metrics that reveal whether search results are genuinely useful.

03Retrieve at scale

Use inverted indexes, approximate nearest-neighbor search, and vector databases.

04Build modern IR systems

Connect retrieval to recommendation, language models, RAG pipelines, agents, and memory.

The course journey

FoundationsBoolean and ranked search
→
RepresentationsWords, images, and vectors
→
PersonalizationRecommendation
→
Generative IRRAG and agents

Weekly syllabus

WeekThemeTopics and practice
1Finding documents

Introduction to IR; Boolean search

2Representing and ranking text

Vector space and bag-of-words models; ranked search; development environment tutorial

3Search engines

Indexing, web ranking, and evaluation metrics

4Learning to retrieve

Machine-learning foundations; probabilistic retrieval; PyTorch and image-processing tutorial

5Visual and vector search

Image-to-image retrieval; approximate nearest-neighbor search

6Meaning and query quality

Word embeddings, query expansion, query-performance prediction, and vector databases

7Personalized search

Search personalization and midterm synthesis

8Recommendation foundations

Collaborative filtering and matrix factorization

9Learned recommenders

Linear and neural recommender systems

10Generative AI for IR

Generative recommendation, prompt engineering, and pretrained language models

11Grounded generation

Retrieval-augmented generation; agentic AI and memory systems

12Connected tools

Model Context Protocol; integration and review

What you will build

Assignment 1A document search engine

Construct an inverted index and retrieve ranked documents.

Assignment 2An image retrieval system

Search visual embeddings using a vector database.

Assignment 3A collaborative recommender

Estimate preferences from patterns across users and items.

Assignment 4A RAG application

Ground language-model responses in retrieved documents.

Assessment at a glance

60% Assignments35% Exams5% Participation

The course uses four individual implementation assignments, a midterm and final exam, and active participation. It is designed as an applied machine-learning course: students should leave able to explain an IR method, implement it, and evaluate whether it works.