One strength of this study is its high external reliability as it gave consistent results every time it was repeated. Bem showed this through the test retest method, asking the same group of participants to repeat the test 4 weeks later. Furthermore, it has high internal reliability, as Bem split the test into two half's and asked the group of participants to complete it, finding that the results from the separate half's were similar. Finally, the 100 students used by Bem to create the BSRI were evenly split into male and female, and only traits chosen by both men and women were used, meaning that the questionnaire is unlikely to have any gender bias.