True or false: Compared with squared-error metrics, mean absolute error is less affected by large prediction errors.
7 Model Evaluation Online Quiz Questions
Use this free practice quiz with 20 questions to review 7 Model Evaluation, test your knowledge, and prepare for your next test or exam.
A team has separate training, validation, and test sets. What is the intended role of the test set?
- A
To tune model settings repeatedly during development
- B
To provide a final estimate of performance after model selection
- C
To fit preprocessing separately for every candidate model
- D
To determine which metric should be used after inspecting test results
In six-fold cross-validation, how many folds are used to train the model in each round? Enter the number of folds.
When unusually large prediction errors are especially costly, may be more informative than MAE.
A screening system must minimize missed positive cases, even if it sends some extra follow-up alerts. Which metric should the team emphasize?
- A
Accuracy
- B
Precision
- C
Recall
- D
ROC AUC
Which quantities are counts recorded in a binary confusion matrix? Select all that apply.
- A
True positives
- B
False positives
- C
True negatives
- D
False negatives
- E
Accuracy
- F
F1 score
What is the name of the classification metric defined as the fraction of predictions that are correct?
If a dataset contains repeated observations from the same people or other units, keep the separated across folds.
True or false: A negative R² means a regression model performs worse than predicting the test-set mean.
- A
True
- B
False
For multiclass precision, recall, or F1, which statements correctly describe averaging methods? Select all that apply.
- A
Macro averaging gives each class equal weight.
- B
Weighted averaging weights classes by their frequency.
- C
Macro averaging weights classes by their frequency.
- D
Weighted averaging gives each class equal weight regardless of frequency.
A classifier outputs scores rather than only class labels. What does ROC AUC summarize?
- A
The model’s performance at one fixed threshold chosen using the test set
- B
The model’s ranking performance across decision thresholds
- C
The fraction of predictions that are correct at every threshold
- D
The average recall across classes
Why can overall accuracy give a misleading impression on an imbalanced classification task? Name a metric that gives each class equal weight and explain what it adds.
A team needs a simple baseline for a classification model. Which prediction rule is given as an example?
- A
Predict a different randomly selected class for every test example
- B
Predict the most frequent class in the training set
- C
Predict the class that gives the highest test-set accuracy after repeated tuning
- D
Predict the least frequent class in the validation set
When comparing two candidate models, which evaluation practice is recommended?
- A
Give each model a different test set so each can be evaluated under its strongest conditions
- B
Use the same data splits for each model
- C
Choose a different metric for each model after viewing test results
- D
Use test-set results repeatedly to choose model settings
A regression system occasionally makes very large errors, and those errors are especially costly. Which metric is more informative for emphasizing this risk?
- A
MAE, because it gives large errors more influence than other errors.
- B
RMSE, because it penalizes large errors more heavily than MAE.
- C
R², because a negative value means large errors are costly.
- D
Accuracy, because it reports error in the target's units.
What classification metric is the fraction of examples predicted positive that are truly positive?
A team needs to tune model settings and then report a final performance estimate. Which use of the validation and test sets best limits an overly optimistic estimate?
- A
Use the test set to tune settings, then use the validation set for the final unbiased estimate.
- B
Use the training set for the final estimate and the test set to select models.
- C
Use the validation set to select models or tune settings, and reserve the test set for final evaluation.
- D
Use the test set repeatedly for model selection so its estimate becomes more reliable.
A classifier is evaluated on a dataset where one class is much more common than the others. Why might its accuracy give a misleading impression of performance?
- A
A model can achieve high accuracy by predicting the majority class while missing most minority-class cases.
- B
Accuracy gives every class equal weight, regardless of its frequency.
- C
High accuracy guarantees that the model finds most examples from every class.
- D
Accuracy measures only the fraction of predicted positive examples that are truly positive.
ROC AUC summarizes ranking performance across decision thresholds, but it does not determine which threshold is best for a particular application.
- A
True
- B
False
In multiclass evaluation, which averaging method weights each class equally rather than weighting classes by their frequency?