This study aims to prove empirically the validity and reliability of Questionnaire on Students' Perceptions of STEM and Problem-solving (SPSP) in learning physics using Rasch model. The questionnaire was disseminated to 59 (N=59) students class XI MIPA in one of Senior High School in Kuningan Regency. Development of SPSP Questionnaire using procedure of product development model 4-D. The stages that will be used consists of four stages, namely: a) define, b) design, c) development, and disseminate. The data obtained were analyzed by means of the Rasch Model. Based on the result of the study, it shows that the SPSP questionnaire had high reliability that 0.90. So, it can be concluded that SPSP questionnaire is reliable and acceptable. While the item validity analysis shows that there are 8 valid items and 1 item does not match the MNSQ benchmark. Outfit value lies between 0.5 <MNSQ <1.5 and also does not meet the ZSTD Outfit criteria (-2.0 <ZSTD <2, 0). Meanwhile, the students' responses indicate that learning in school has not supported STEM activities and problem solving. So it is necessary to develop learning in schools that can support STEM activities and students' problem solving abilities

This study aims to determine the creative thinking skills at optic instruments of Sundanese tribe, 11th-grade students. This research is a case study research conducted at a high school in Majalengka district, West Java. Totaling 32 students consisting of 12 male students, namely “Aa”, 20 female students, namely “Teteh”, and 18 Sundanese, the rest are immigrants. The instrument used is the Test for Creative Thinking-optical instrument (TCT-OI) which has existed validated by experts. The data found were investigated with Rasch Analysis Model (RAM). Based on the results of the analysis using the Rasch Analysis, it was found that the creative thinking ability of students stayed static low can be shown by the value of Person reliability which is 0.21 included in the weak category. There are variances in the level of creative thinking skills of students from the Sundanese and non-Sundanese tribes. As a result, it is necessary to develop creative thinking skill on the optical instrument, 11th grade students Sundanese tribe