Final answer:
If an expected result is not specified in a test, it may be difficult to determine whether the test has passed or failed. This does not prevent the test from being run or automated, but it affects the evaluation of results. Both expected and unexpected results require scrutiny to validate observations.
Step-by-step explanation:
When running a test, having a clearly specified expected result is crucial for determining whether the test has passed or failed. If the expected result is not specified, option C is correct: It may be difficult to determine if the test has passed or failed. This is because without knowing what outcome is anticipated, we cannot effectively measure the success of the test against any criteria.
However, this does not mean that the test cannot be run (option A) or that automation is impossible (option D); rather, it signifies that the evaluation of results may be compromised, potentially leading to inconclusive or inaccurate conclusions about the system's performance.
Regarding the criteria for expected versus unexpected results, while certain thresholds or standards must be met for a result to be valid, the strictness of these criteria may vary. Expected results often have predetermined criteria based on previous observations or theoretical predictions, whereas unexpected results may prompt a more rigorous examination to understand the anomaly. Nonetheless, both require a degree of scrutiny to ensure reliability and validity of observations.