Symptoms of inattention (IA), hyperactivity, and impulsivity present in school-aged children are important indications of developmental problems. The assessment of these symptoms largely relies on questionnaires completed by parents, teachers, and the children themselves. However, inherent perceptual biases may lead to inaccuracies in these evaluations. This study investigates the biases among different respondents for 41 elementary-aged students (19 male and 22 female) by analyzing their responses on the attention-deficit/hyperactivity disorder-rating scale (ADHD-RS) through a novel virtual reality-based objective measure (AttnKare-D). Correlation analysis reveals higher agreement between parents and students compared to other informant pairs. Nevertheless, when compared with the objective measure, parents and students do not exhibit distinct separation between high and low-scoring samples, whereas teachers demonstrate significant separation on various objective measure factors. This discrepancy suggests that teachers may possess a more accurate baseline for peer-related measurements, leading to a more objective evaluation of ADHD symptoms. However, it is essential to acknowledge that teachers are not entirely exempt from biases. Gender-specific comparisons reveal notable differences, with male children showing the largest separation in distractibility and female children in movement. In conclusion, this study emphasizes the significance of recognizing and addressing potential biases when interpreting questionnaires assessing symptoms of IA, hyperactivity, and impulsivity in children.