The basic physical meaning of temperature modulation for DSC is an arguable research topic, and its interpretation affects the development of thermal analysis and polymer science. This article studies the basic physical meaning of TMDSC by numerical simulation. DSC and TMDSC output curves are computed for a sample with step changes in its specific heat and for a sample with crystallites melting over the temperature range. The TMDSC curves are further analyzed to obtain the reversing and nonreversing components. It is shown that separation of the reversing and nonreversing components from the underlying heat flow cannot be justified. Some common misconceptions regarding TMDSC are discussed as well. (c) 2007 Wiley Periodicals, Inc.