This study assessed the extent to which students commit various types of errors when completing Holland's Self-Directed Search (SDS) entirely on their own. Nearly all students made some type of error and approximately half of the students made errors that affected their final 3-letter summary codes. Almost one-fifth of the students made errors resulting in an incorrect high-point code. Whether or not students made errors that affected their summary codes was unrelated to the extent to which they were interested in knowing more about occupations or academic majors they might like. Neither were such errors related to whether students felt the occupations suggested by their summary codes seemed reasonable. Only slightly over one-third of the students actually did feel that the occupations seemed reasonable. (Author)