The purpose of this study is to clarify, compare and contrast the features of the Modified Grounded Theory Approach (M-GTA) and Trajectory Equifinality Model (TEM) methodologies and to explore the possibility for using them to describe children's experiences in the field of early childhood education and care. These are qualitative research methodologies. First, in this the study, cases were collected by observing the scene where a target child carries out a target activity in a kindergarten classroom setting. Next, the cases were analyzed based on the common research question, using both the M-GTA and TEM approaches. By examining and analyzing the results using each methodology, it was clear what kind of knowledge is acquired from cases by using each methodology, and what kinds of problems each methodology has. Further examination showed that the feature in M-GTA that describes the process of a child's experience provides a structure and framework for explaining a child's activity. On the other hand, it became clear that the TEM approach describes the process of a child's experience itself, and that a TEM analysis can lead to great understanding of an individual child's experiences and transformation