Respond is related to Answer. Answer is related to Mistake. 
Frequency is a type of Ratio. Frequency is the opposite of Period. Period is related to Future. Future can be Uncertain. 
Respond <--RelatedTo--> Answer <--RelatedTo--> Mistake 
Ratio <--IsA-- Frequency <--Antonym--> Period <--RelatedTo--> Future --HasProperty--> Uncertain 