The campus safety committee has asked Professor Ibrahim to study bicycling on his campus. He trains two observers and has them observe the number of cyclists and their safety at various points around campus. Initially, the observers can't agree about what is dangerous behavior. Professor Ibrahim refines his codebooks to clearly define the rating scales and retrains the observers. Which is he addressing by doing this?

The reliability of the measurement can be described or explained as how consistently a method is able to measure an event. This means that, when the same result can be consistently gotten or achieved through the use of same methods under the same circumstances, then the measurement is considered reliable.

In this case, the good Observations are that, both trained observers are reliable and valid. But Professor Ibrahim is trying to make the judgments more reliable, this is by defining the rating scales and retraining the observers which will ensure construct validity.