The results of mathematical modeling of trophic relationships between individual components of ecological communities significantly depend on the features of the functional response of predators (consumers). For this reason, the adequacy of the results of modeling ecological processes is largely determined by the choice of a mathematical function that describes the functional response. The choice of the type of such a function is the subject of intense discussion. In particular, the problem of predator interference and the associated choice between two types of functions describing the functional response in mathematical modeling of population dynamics are widely discussed. It is the choice between predator-dependent and prey-dependent functions. Here we present the results of comparing a wide range of the functions describing the functional response, which are used in modeling trophic interactions, with the functional response that is characteristic of interactions between phytoplankton and zooplankton populations in the ecosystem of the Naroch Lakes (Belarus). We apply the knowledge-and-data-driven, or KDD, approach, which allows us to use the results of the monitoring of the Naroch Lakes ecosystem, to identify the time-dependent functional response in each of the reservoirs of this ecosystem. The KDD approach provides for direct input of monitoring data into the mathematical description of population dynamics. As a result, we show that predator-dependent functional responses best match the environmental processes in the ecosystem of the Naroch Lakes.