course @ Sofia University
Lab notes by Elitsa Yotkova and Kristina Kalemdzhieva
| Topic | Description | Notes | Quiz | Slides |
|---|---|---|---|---|
| 00Introduction | Who we are and a map of the course: search, machine learning and language models | Learn → | Quiz → | Coming soon |
| 01Uninformed Search | Basic definitions, state spaces, and blind search strategies (BFS, DFS, UCS, IDS) | Learn → | Quiz → | Present → |
| 02Informed Search | Heuristic functions, greedy search, A* algorithm, and optimization techniques | Learn → | Quiz → | Present → |
| 03Constraint Satisfaction | CSP fundamentals, backtracking, arc consistency (AC-3), and min-conflicts heuristics | Learn → | Quiz → | Present → |
| 04Genetic Algorithms | Evolutionary search, selection mechanisms, crossover, mutation, and metaheuristic optimization | Learn → | Quiz → | Present → |
| 05Games | Adversarial search, game trees, minimax, and alpha-beta pruning | Learn → | Quiz → | Coming soon |
| 06Introduction to ML | Core concepts, bias and variance, regression and classification, KNN, SVM, Naive Bayes, decision trees, and K-Means | Learn → | Quiz → | Coming soon |
| 6.5Linear & Logistic Regression | Cost function, gradient descent and the closed form, R² and RMSE, logit and sigmoid, cross-entropy, one-vs-rest and softmax | Learn → | Quiz → | Coming soon |
| 07K-Nearest Neighbours | Global vs local, instance-based vs model-based and lazy vs eager learning, distance metrics, choosing K, KNN classification and regression | Learn → | Quiz → | Coming soon |
| 08Naive Bayes Classifier | Bayes' theorem, conditional independence, spam filtering, the zero-probability problem and Laplace smoothing, Gaussian Naive Bayes | Learn → | Quiz → | Coming soon |
| 09Decision Trees | Classification and regression trees, recursive construction, entropy as expected surprise, information gain, ID3 in Python, overfitting, pre- and post-pruning | Learn → | Quiz → | Coming soon |
| 10K-Means and Clustering | Unsupervised learning, the K-means algorithm and its cost, local optima and random restarts, the elbow method and silhouette analysis, K-means++, soft K-means, hierarchical clustering and linkages, cluster evaluation metrics | Learn → | Quiz → | Coming soon |
| 11Neural Networks | The artificial neuron and activation functions, logic gates and XOR, multilayer perceptrons and universality, gradient descent, perceptron learning, back-propagation, handwritten digit recognition | Learn → | Quiz → | Coming soon |
| 12Transformers and Generative Models | Subword tokenization and BPE, embeddings and position, self-attention with queries, keys and values, causal masking, MLP and residual connections, logits, softmax and temperature, text generation | Learn → | Quiz → | Coming soon |
| 13Post-training and Alignment | Pretraining vs SFT vs preference learning, reward models and RLHF, the KL constraint, reward hacking and Goodhart's law, DPO, human and AI feedback, outcome vs process supervision, verifiable rewards, evaluation | Learn → | Quiz → | Coming soon |
| 14Evaluation, Metrics and Data Analysis | Task vs metric vs evaluator, precision, recall and F1, BLEU, ROUGE-L and COMET, LLM-as-a-judge and its biases, reading plots, subgroup analysis, distribution shift, data leakage and contamination, uncertainty, human evaluation | Learn → | Quiz → | Coming soon |
SemEval is the yearly international workshop on semantic evaluation: organisers publish a task with data and a metric, teams build systems, and all systems are scored on the same hidden test set.
We are among the organisers of Task 9: Dr. Dimitar Dimitrov, Elitsa Yotkova and Prof. Ivan Koychev, together with Giovanni Da San Martino, Preslav Nakov, Jakub Piskorski and colleagues from Padova, MBZUAI, Helsinki, Porto, Beira Interior and ETH Zurich. It builds on the SemEval-2023 task on persuasion techniques, framing and news genre.
Framing is choosing which aspects of an issue to make salient, so that a reader takes away a particular meaning. Images can reinforce, complement or contradict the framing of the text.
Labs · Teaching Assistant · Author of these notes
Master's student in Information Retrieval and Knowledge Discovery @ Sofia University, ex-Google, Uber
Previously at
Labs · Teaching Assistant · Author of these notes
Master's student in Information Retrieval and Knowledge Discovery @ Sofia University, ex-AWS
Previously at
Lectures
Sofia University "St. Kliment Ohridski", Faculty of Mathematics and Informatics
The course is also taught by other teaching assistants; this site contains only our lab notes.