An instructor finds that the standard, formal assessment towards the end of a given course yields
erratic learner scores over a broad spectrum. During the course, the instructor observed all of the
learners progressing at about the same pace. In this situation, which of the following is the MOST

likely source of the results?

A.
The formal assessment lacks validity.

B.
The formal assessment lacks reliability.

C.
The observation lacked validity.

D.
The observation lacked reliability.

Explanation: