Nó classification is a key task in the field of graph-based aprendizado de máquina, where the objective is to assign labels or categories to nodes within a graph. A graph consists of nodes (also called vertices) connected by edges, representing relationships or interactions between them. Examples of graphs include social networks, citation networks, and biological networks.
In node classification, each node typically has associated features, which can be numerical or categorical data that describe various attributes of the node. The classification process involves utilizing these features, along with the graph’s structure (i.e., the connections between nodes), to infer the correct category for each node. This task can be performed using various técnicas de aprendizado de máquina, including supervised, semi-supervised, and aprendizado não supervisionado métodos.
A classificação supervisionada de nós requer dados rotulados, where some nodes come with known categories. The classifier learns from this labeled data to make predictions for unlabeled nodes. Aprendizado semi-supervisionado, on the other hand, leverages both labeled and unlabeled data, which is particularly useful in scenarios where obtaining labels is expensive or time-consuming. Unsupervised methods might cluster nodes based on their features or connectivity without prior labels.
Node classification has numerous applications, such as identifying communities in social networks, classifying products in recommendation systems, detectando atividades fraudulentas, and analyzing biological networks to understand disease mechanisms. With the advent of deep learning techniques, particularly redes neurais de grafos (GNNs), node classification has become more effective, enabling the modeling of complex relationships within graphs.