Concept Drift Detection

Question 1

What are the three types of concept drift changes?

Answer 1

1. Gradual Changes
2. Abrupt Changes
3. Recurring or cyclical changes

Question 2

What are three drift detection algorithms?

Answer 2

1. Adaptive Windowing method for concept drift detection (ADWIN)
2. Drift Detection Method (DDM)
3. Early Drift Detection Method (EDDM)

Question 3

How does ADWIN work?

Answer 3

It maintains a window of variable size that adjusts itself in the face of a drift. This means it keeps the most recent data points in the stream and discards the older ones, growing the window when no change is detected and shrinking when it is.

Question 4

How does DDM work?

Answer 4

DDM provides equations for comparing error rate and standard deviation to detect when drift is taking place.

if pi + si >= pmin + 2smin -> Warning Zone
if pi + si >= pmin + 3smin -> Change Detected