Transient experiments can provide more information than steady-state experiments and are particularly useful in unraveling complex reaction networks. Modeling of the data allows to obtain quantitative information, e.g., sorption and rate constants as well as diffusion coefficients. To ensure correct estimation of the model parameters operating conditions that aim at eliminating diffusion resistances have to be defined as well as identification of the accessible parameters. Moreover, a statistical analysis of the model and its parameters after regression has to be performed. These issues are discussed here for temporal analysis of products (TAP) experiments as an example of a transient technique. (c) 2006 Elsevier B.V. All rights reserved.