Welcome

This course returns to Hornos Lumbre with another question. You already know that the agent's forecast loaded onto the heat what the calendar was doing; now you are going to redo it yourself, with your copilot, and see how far the fix goes. It writes the code: your job is to read each dial, compare the model with a simple rule and write down what it is worth and what it still has to prove. Have the case data to hand (daily sales, stores and weather) and an assistant that can run code on them.

What you will find

• Block 1. Several variables: reading the dials of a regression. From one dial to several: what each coefficient means, what happens when a variable is missing and how categories and interacting effects are put into a model. First reading of the case: the temperature dial.
• Block 2. Forecasting over time: trend, seasonality and the no-model rule. A sales series has trend, seasonality and noise. Before modelling it you need the common-sense rule that every model must beat, and to examine without shuffling time. Second reading of the case: August.
• Block 3. Classifying: from probability to the tree. Predicting a yes or a no is estimating a probability and setting a threshold. Two models that can be read: logistic regression and the decision tree. Third reading of the case: will tomorrow be a weak day?
• Block 4. Many trees, and when not to train anything. Averaging many trees is usually more accurate and harder to explain. And today's question: for a given task, do you train a model of your own or ask one that is already trained? Last reading of the case: the model card handed to Elena.

How you will work

Each lesson opens with a short introduction and, below it, several pills: short pieces that explain a single idea and end with a case or something to do. Read them in order the first time; afterwards you can go back to the one you need.

Where you see an interactive practice, do it before reading on: it is there for you to decide, calculate or classify, and the explanation comes afterwards. It does not save what you write, so copy whatever you want to keep.

Each block ends with an exam of six questions. All the answers come with a comment, including the wrong ones: failing and reading why is part of the method.

At The Singular Academy you learn by solving real cases. If at the end of a lesson you do not know what you would do differently tomorrow, go back over it.