What might cause a test to be unreliable?

A test may be unreliable due to factors such as inconsistency in its administration, scoring errors, or ambiguous questions that lead to varied interpretations. Environmental influences, like distractions during testing, can also affect performance. Additionally, if the test doesn't accurately measure what it intends to assess, its reliability diminishes. Lastly, a small or unrepresentative sample size can further compromise the test's reliability.