Elbow method

The Elbow method is a technique used to determine the optimal number of groups or clusters in data analysis, particularly with clustering algorithms like k-means. It involves plotting how well the data fits into different numbers of clusters, measuring this with a metric called within-cluster sum of squares (WCSS). As the number of clusters increases, WCSS decreases, but with diminishing returns. The best number of clusters is identified where the decrease levels off, forming an "elbow" in the graph. This point balances simplicity and accuracy in grouping data.