Advantages

One of the main advantages of standardized testing is that it is able to provide assessments that are psychometrically valid and reliable, as well as results which are generalized and replicable.

Another advantage is aggregation. A well designed standardized test provides an assessment of an individual's mastery of a domain of knowledge or skill which at some level of aggregation will provide useful information. That is, while individual assessments may not be accurate enough for practical purposes, the mean scores of classes, schools, branches of a company, or other groups may well provide useful information because of the reduction of error accomplished by increasing the sample size.

While standardized tests are often criticized as unfair, the psychometric standards applied in the development of standardized tests would produce fairer testing if applied in other types of testing. In particular, the effectiveness of each test item in accomplishing the goal of the test would have to be demonstrated.