BloodFlowAR: Development of an Augmented Reality Application as a Visual Learning Medium for the Human Blood Circulation System

The human blood circulation system is one of the most abstract and challenging topics for elementary school students, as it involves internal organs and processes that cannot be directly observed. Traditional teaching methods such as textbooks and two-dimensional diagrams are often insufficient to provide meaningful understanding. This study aims to develop BloodFlowAR, an Android-based augmented reality (AR) application built in Unity, designed as an interactive visual learning medium for Grade 5 elementary students. The development followed the ADDIE model (Analysis, Design, Development, Implementation, Evaluation). The application enables students to visualize the blood circulation system in three dimensions by scanning a marker card, displaying animated 3D models of the heart, blood vessels, and blood flow direction in real time. Data were collected through expert validation questionnaires (media and material validators), practicality questionnaires (teacher and student responses), and learning outcome tests (pretest and posttest). The validity test results showed that the media validator gave a score of 92.5% and the material validator gave 95.0%, both categorized as very valid. Practicality test results showed teacher responses of 90.6% and student responses of 91.7%, both categorized as very practical. The media's effectiveness was evaluated using the N-Gain formula, which produced a value of 0.37, categorized as moderate improvement. These results indicate that BloodFlowAR is valid, practical, and moderately effective as a visual learning medium for the human blood circulation system at the elementary school level. Keywords: Augmented Reality, Blood Circulation System, Unity, Elementary School, ADDIE