One is a pronoun in the English Language. It is a gender-neutral indefinite pronoun. Roughly meaning "A Person".
I believe the answer is :produces the same results from one time to the next
When the result of a certain test is generally the same from one another, we can infer that the test result does not happen because some sort of 'luck' or random events. As the rate of unforeseen circumstances such as luck reduced, the reliability of the test would be increased .
