It is not uncommon to use what are called diagnostic, placement, readiness or competency tests once students arrive at university to gauge their basic skills in mathematics or literacy. This paper begins by discussing diagnostic mathematics tests and identifying the key reasons for which these are run. Two such tests with repercussions for students are discussed. These two tests are for different student cohorts and are run for different reasons. We identify the purposes for which the tests were developed, and actions which eventuated. We identify any additional purposes the tests served beyond those intended. The tests had a positive impact on student learning. It is not uncommon to use what are called diagnostic, placement, readiness or competency tests once students arrive at university to gauge their basic skills in mathematics or literacy. This paper begins by discussing diagnostic mathematics tests and identifying the key reasons for which these are run. Two such tests with repercussions for students are discussed. These two tests are for different student cohorts and are run for different reasons. We identify the purposes for which the tests were developed, and actions which eventuated. We identify any additional purposes the tests served beyond those intended. The tests had a positive impact on student learning.It is not uncommon to use what are called diagnostic, placement, readiness or competency tests once students arrive at university to gauge their basic skills in mathematics or literacy. This paper begins by discussing diagnostic mathematics tests and identifying the key reasons for which these are run. Two such tests with repercussions for students are discussed. These two tests are for different student cohorts and are run for different reasons. We identify the purposes for which the tests were developed, and actions which eventuated. We identify any additional purposes the tests served beyond those intended. The tests had a positive impact on student learning.It is not uncommon to use what are called diagnostic, placement, readiness or competency tests once students arrive at university to gauge their basic skills in mathematics or literacy. This paper begins by discussing diagnostic mathematics tests and identifying the key reasons for which these are run. Two such tests with repercussions for students are discussed. These two tests are for different student cohorts and are run for different reasons. We identify the purposes for which the tests were developed, and actions which eventuated. We identify any additional purposes the tests served beyond those intended. The tests had a positive impact on student learning.