Active learning (active learner algorithm)

Active learning is a machine learning methodology in which a model is incrementally trained using a small amount of data that is labeled by a human expert. The model is then used to label additional data, which is used to train the model further. The process is repeated until the model converges on a sufficiently accurate representation of the data.

Active learning is useful when labeled data is scarce, as it allows the model to learn from a small amount of data and avoids the need for extensive human labeling. It is also efficient, as it only labels data that is needed to train the model.

Active learning algorithms typically use a heuristic to select which data to label next. The most common heuristic is uncertainty sampling, which selects data that the model is least certain about. Other heuristics include density-based sampling, which selects data that is densely clustered, and representative sampling, which selects data that is representative of the overall distribution.

Active learning is a close cousin of semi-supervised learning, which also uses a small amount of labeled data to train a model. The difference is that in semi-supervised learning, the model is also trained on a large amount of unlabeled data, while in active learning, the model is only trained on the labeled data.

What is an active learning model?

Active learning is a machine learning technique that is typically used in situations where labeled data is scarce. In active learning, the model is first trained on a small amount of labeled data, and then the model is used to label additional data points. The model is then retrained on the labeled data, and the process is repeated until the desired accuracy is achieved.

Active learning is often used in situations where it is expensive or difficult to label data points, such as in medical applications where experts must label data points. Active learning can also be used to improve the accuracy of a model by selectively labelling data points that are most likely to be mislabeled by the model.

What is active learning strategies machine learning?

Active learning is a neural network pattern recognition technique as well as a machine-learning methodology employed to make the most effective use of the data and eliminate bias. It is a data-driven approach that is initiated by the user who can be more selective in the use of data, which is "the act of selecting which are to be used to solve a task." The advantage to using a technique like active learning "is that many problems, like recognizing objects in pictures or facial recognition, are easier the more data is used. So, “passive” neural networks that only use a dataset as it is provided will usually perform worse than “active” neural networks that select relevant data."

The above definition of active learning is from the "Neural Network Pattern Recognition" article on Wikipedia.

Is active learning supervised learning?

Active learning is a type of supervised learning. In active learning, the learner is given a set of unlabeled data and must choose which data to label. The learner then uses the labeled data to train a model. Active learning is often used when labeling data is expensive or time-consuming.

What is an example of active learning?

Active learning is a neural network pattern recognition technique as well as a machine-learning methodology employed to make the most effective use of the data and eliminate bias. It is a data-driven approach that is initiated by the user who can be more selective in the use of data, which is "the act of selecting which are to be used to solve a task." The advantage to using a technique like active learning "is that many problems, like recognizing objects in pictures or facial recognition, are easier the more data is used. With enough data, all the variants of a desired pattern will be found by a machine-learning algorithm. So, “passive” neural networks that only use a dataset as it is provided will usually find only 70% or so of all the desired patterns. “Active” neural networks that select relevant data will often find almost all desired patterns. The trade-off is that active learning takes more time to find the desired patterns.

The above definition and example of active learning is from the website "What is Active Learning?"