Continuum

In the realm of psychology (which is a real science based on the scientific method), a continuum is one of the newer and more preferred ways of classifying psychological disorders, and is currently on its way to replace the outdated categorical approach in the DSM-6.

It has been proven that the dimensional approach (which uses a continuum) is far more superior than the categorical approach. When using the categorical model, if someone didn't meet at all the criteria for depression then they wouldn't be diagnosed with depression. This is problematic as obviously that person has depression to some extent. Essentially the dimensional approach introduces a continuum where instead of relying on fixed criteria, it instead uses a continuum of ranging from most healthy to least healthy (which can be thought of as a numerical scale). Therefore, using a continuum provides much greater accuracy and precision in diagnosing disorders.

In order to gain greater accuracy in diagnosing NPD, the psychologist used the dimensional approach instead, which measures on self-centeredness on a continuum of low to high.