The survey's lack of representativeness means it can't accurately reflect the whole population's views.

representativeness 是由形容词 representative（有代表性的）加上名词后缀 -ness 构成的名词形式，表示"代表性"这个抽象概念。representative 本身由动词 represent（代表）加形容词后缀 -ative 构成。