This chapter explores three analytical approaches—variable-centered, person-centered, and person-specific—that span a spectrum of generalizability and individualization. The variable-centered approach emphasizes generalizable insights by analyzing relationships across a population, often overlooking individual heterogeneity. The person-centered approach identifies distinct subgroups within populations to reveal shared patterns and characteristics among similar individuals. The person-specific or idiographic approach shifts focus entirely to the individual, offering a detailed examination of intra-individual variability and processes over time. The chapter includes a tutorial using R, demonstrating how these methods can be applied to educational data using Experience Sampling Method (ESM) data on students’ task value and happiness, we illustrate the strengths and limitations of each approach in understanding the relationship between these two variables.