This is the 5193rd most frequent Russian word.
нетрадиционных
"Нетрадиционных" means "non-traditional" or "unconventional."
In this sentence, 'нетрадиционных' is used to describe 'подходов' (approaches) and conveys the meaning of 'unconventional' or 'nontraditional' methods.
Он интересуется нетрадиционных подходов в науке.
He is interested in unconventional approaches in science.
Here, 'нетрадиционных' is attributing to 'взглядов' (views), emphasizing the distinct or unconventional nature of such opinions.
Нетрадиционных взглядов всегда было трудно принять.
Nontraditional views have always been difficult to accept.
In this usage, 'нетрадиционных' modifies 'материалов' (materials), referring to building resources that are unconventional or not standard.