In machine learning

Machine learning

Machine learning, a branch of artificial intelligence, is a scientific discipline concerned with the design and development of algorithms that allow computers to evolve behaviors based on empirical data, such as from sensor data or databases...

, multi-label classification is a variant of the classification problem where multiple target labels must be assigned to each instance. Multi-label classification should not be confused with multiclass classification

Multiclass classification

In machine learning, multiclass or multinomial classification is the problem of classifying instances into more than two classes.While some classification algorithms naturally permit the use of more than two classes, others are by nature binary algorithms; these can, however, be turned into...

, which is the problem is categorizing instances into more than two classes.

Several strategies exist for multi-label classification; a common one is the one-vs.-all (or one-vs.-rest, OvA or OvR) strategy, which consists of training a single classifier for each class that can distinguish that class from all others.