Choosing ML models and algorithms: MLA-C02 study notes and practice questions
What to know about Choosing ML models and algorithms for the MLA-C02 exam, from the ML Model and Foundation Model (FM) Development domain (24% of the exam guide), then 1 free question to test it. Part of the MLA-C02 study guide.
No labels, find structure: unsupervised (clustering, anomaly detection, PCA).
Learning from rewards: reinforcement learning.
Interpretability vs performance
Linear models and shallow trees are easier to explain; gradient-boosted trees and deep networks often score higher. Regulated decisions may favor simpler models or need SHAP explanations.
Common traps
Linear Learner for forecasting many time series. Use DeepAR.
k-means for labeled data. It’s unsupervised.
Random Cut Forest for forecasting. It detects anomalies.
A solar installer operates 2,000 residential systems across three states. For each site, it needs a daily forecast of energy output for the next 30 days, and it has three years of daily production history per site with strong seasonal patterns.
Many sites share similar weather and seasonal behavior, so the team wants one model that learns from all of them together. The forecasts must come with uncertainty ranges, and the team wants a built-in algorithm in SageMaker AI.
Which algorithm should the ML engineer choose?
Choose one answer.
AA. Linear Learner, trained on one row per site with the average output as its target.
BB. DeepAR, trained on all site time series together, which produces probabilistic forecasts for each series.
CC. K-means, to cluster the sites and then forecast each cluster with its average output.
DD. Random Cut Forest, trained on all site histories, to flag days whose output is unusual and use the flagged days as the forecast.
Show the answer and explanation
Answer: B
A. Wrong: Linear Learner treats rows independently and would average away the daily pattern and seasonality the forecast needs. It does not produce a forecast for each day with uncertainty ranges.
C. Wrong: K-means finds groups but does not produce forecasts over time. Averaging clusters would also hide the daily pattern for each site.
D. Wrong: Random Cut Forest is an anomaly detector and does not produce future values. Flagging unusual days does not give the 30-day forecast the installer needs.
Explanation
DeepAR is a built-in algorithm for forecasting many related time series, and it outputs probabilistic forecasts that include intervals. Linear Learner loses the time structure, k-means does not forecast, and Random Cut Forest detects anomalies rather than predicting values.
Want more on Choosing ML models and algorithms? The 5 full-length practice sets have 9 more Choosing ML models and algorithms questions, 325 in all, none of them in the free exam. One payment of $14.99, no subscription. See the practice sets →