Table 1.

This table illustrates a toy time series consisting of values 1-10 and three engineered features, lag 1, lag 2, and lag 3. The training set consists of values above the highlighted box while the test set consists of the last three values inside the box. The values bolded in red illustrate instances of data leakage since the values 8-10 would not be known in an actual predictive scenario.

TS	Lag 1	Lag 2	Lag 3