With qualitative data, it's not as easy to use statistics and it's often more difficult to make an argument that the results are meaningful. However, there's an important distinction that qualitative data can be more intuitive and make more sense, even if it doesn't involve numbers.

Some data can be converted to either type of data. You may have test results that range from 0 to 100, which would be quantitative. You could also convert scores to a qualitative scale, such as poor to average to good. What can you see as possible benefits of using either of the two methods when describing grades?