Apart from basic skills such as self-care and speaking, higher-order cognitive skills including inquiry, critical thinking, and scientific thinking can develop during early childhood. Thus, it is crucial to employ teaching methods that support the development of higher-order cognitive skills in these age groups and ensure that these children systematically use such skills.This study aimed to investigate the effects of the POE (Predict-Observe-Explain) method on the POE and critical thinking skills during early childhood. In this context, 27 pre-school students participated in the study, which involved an experimental design and was carried out for six weeks. In the study, the data collected by using quantitative and qualitative data collection tools were analyzed using appropriate analysis methods. The researchers compared the effects of scientific experiments prepared in line with the POE and gamification on students' critical thinking skills through philosophical inquiry (CTSPI) and POE skills, and skills that constitute the sub-dimensions of these skills. The findings revealed that in early childhood education the POE was more effective than gamification in developing students' critical thinking and POE skills. Similarly, teachers participating in the research process thought that the POE was more effective than gamification in motivating students and turning their attention to teaching processes. Considering the results, the POE is recommended to be used in early childhood education, especially in transferring scientific content in the fields of science.