TASK DEFINITION: Given a category and a set of five words, find the word from the set that does not belong (i.e. is the least relevant) with the other words in the category. Words are separated by commas.
PROBLEM: Category: military rank 
Words: sargent, ordinary, captain, colonel, general

SOLUTION: ordinary

PROBLEM: Category: ocean 
Words: current, data sets, main, sea, wave

SOLUTION: data sets

PROBLEM: Category: window material 
Words: glass, spyhole, handle, coating, knive

SOLUTION:
knive