Question

Why aren't descriptive investigations repeatable?

Answer 1

Descriptive investigations are mainly questions to uncover information.  it  does not have an hypothesis.  It is mainly gathering information, it is not repeatable as you are just asking questions

Answer 2

Descriptive investigations are not repeatable because they are based only on observations made at a single point in time. The results may vary at a different time. In addition, descriptive investigations do not contain variables that may indicate cause-and-effect relationships.