A field-parametrized model termed the Inter-Layer Diffusion Model (ILDM) is developed and is implemented for the probabilistic description of scalar mixing in homogeneous turbulent flows. The essential element of the model is based on the lamellar theory of mixing in the context developed by Kerstein (1991a), and proposes that there are two coupled mechanisms by which the mixing process is described. These mechanisms are due to: (1) local events and (2) integrated global events. The mathematical formalities by which the closure is invoked are described and it is shown that the conditional expected diffusion of the scalar field depicted by the model depends more directly on the local events. With the manipulation of each of these two mechanisms, several families of scalar probability density functions (pdf＇s) are generated. These families include some of the distributions generated by other mixing closures. The similarity of local events imply the similarity of the conditional expected diffusion as generated via these models. The global events manifest themselves by the evolution of the conditional expected dissipation, and also the boundedness of the composition domain. While the pdf＇s generated in this way are very different, their applications for modeling of mixing limited reactions do not yield significantly different results.