Exercises E11-6 - A change in depreciation, depletion, or amortization method is considered a change in accounting estimate that is achieved by a change in accounting principle. We account for these changes prospectively, exactly as we would any other change in estimate. One difference is that most changes in estimate do not require a company to justify the change. However, this change in estimate is a result of changing an accounting principle and therefore requires a clear justification as to why the new method is preferable. (p. 608)