The correct technique is story point estimation because the team is comparing the relative size of work items rather than calculating exact hours, dates, or costs. Story points are commonly used in agile environments to estimate effort, complexity, uncertainty, and risk in relation to other backlog items. PMI's Lexicon defines a story point as "a unit used to estimate the relative level of effort needed to implement a user story." This directly matches the question's requirement to compare relative sizing. Project task estimation is broader and may apply to duration, effort, or cost in predictive planning, but it does not specifically indicate relative sizing. Dependency planning identifies sequencing relationships between work items, not size. Sprint planning is the event where the team selects and plans work for a sprint; it may include estimation discussions, but it is not itself the estimation method. In agile practice, relative estimation helps teams avoid false precision and create a shared understanding of work magnitude. References/topics: Agile Estimation, Story Points, Relative Sizing, User Stories, Adaptive Approaches.