This is the 14484th most frequent Russian word.
ошибочны
Erroneous.
The word "ошибочны" describes the quality of being incorrect or mistaken concerning the assumptions being discussed.
Ваши предположения о причинах аварии ошибочны.
Your assumptions about the causes of the accident are mistaken.
Here, "ошибочны" evaluates the nature of someone's actions as untrue or incorrect.
Она считала, что его действия ошибочны.
She believed that his actions were wrong.
The adjective "ошибочный" (which "ошибочны" is derived from when plural) characterizes the quality of the approach as being flawed or wrong.