thinQmaster Virtual testing partner Adaptive practice exams that find your weak spots and drill them. Every answer explained. From $69
Enroll

thinQmaster

Find your exam

Five questions free, before you decide.

Step 1 · choose a vendor

In one of our camps? Your practice exams come with the tuition — they are on your study page already.

AI & Machine Learning · Foundational

Imputation

Filling in missing values in a dataset with estimated substitutes.

Definition

Simple imputation uses the mean, median or mode; advanced methods use k-NN, regression or iterative models to predict missing values. Adding a missing-indicator feature can preserve information about missingness. Dropping rows is an alternative only when missing data is rare and random.

Example

Replacing missing income values with the median income.

Exam tip

Median imputation is more robust than mean imputation when the feature has outliers or skew.

Related terms