A model that uses data grouped into segments (e.g., age 6 to 8, or first year at college, or start-up companies) whose behavior is tracked over time. Predictions are made for the cohorts as they age. Cohort models are commonly used in demographic forecasting. For example, an analyst could forecast the number of students entering high school in six years by determining the number of students currently in the third-grade cohort in that region (assuming no deaths or net migration).