Study of changes, the relationship of one period to a previous period. The process involves graphs in which the data is displayed in an inverted right triangle, hence, the term “triangulation.” The purposes are as follows: 1) captures changes in ultimate value resulting from natural claim development, 2) reflects changes in losses after initial reserve is established (new information), 3) reflects growth in losses due to IBNR claims, and 4) determines loss payment pattern over time.