Of all the questions on the scale, Sell considered those assessing sexual attraction to be the most important as sexual attraction is a better reflection of the concept of sexual orientation which he defined as "extent of sexual attractions toward members of the other, same, both sexes or neither" than either sexual identity or sexual behavior. Identity and behavior are measured as supplemental information because they are both closely tied to sexual attraction and sexual orientation. Major criticisms of the SASO have not been established, but a concern is that the reliability and validity remains largely unexamined.