The document describes a study that aimed to develop a scale called the Heuristics and Biases Scale (HBS) to measure individual vulnerability to cognitive biases. Undergraduate students were involved in the initial development of items for the scale. Students learned about heuristics and biases and then developed items targeting specific biases. The developed items were piloted in a questionnaire with 128 participants. Results indicated the items formed reliable scales and students reported learning outcomes were achieved. The study provides preliminary evidence that involvement of students can contribute to development of a psychometric tool and enhance learning through problem-based learning approaches.