Practically level of design element (i.e., explore, sharing, connect) is an essential of heutagogical approach. The self-determined learning process can be at ease with the implementation of these elements, and the critical step is reliability to measure teaching and learning feedback. Although various instruments were proposed in the literature to assess heutagogy elements, the specific potential Rasch Measurement Model to determine the practicality levels of heutagogy element is less emphasized. This paper aimed to validate the research instrument (six constructs with 65 items). The instrument was administered to N=175 students for a pilot study. The Rasch model was conducted to examine reliability (0.93, 0.94) with α = 0.97, separation index (3.75, 4.01) for item and person, respectively. Besides, item fit (three-item dropped), polarity and standardized correlation residual (no overlapping items). The findings have shown that the instrument has high validity and reliability for use in measuring the practical level of heutagogy elements.