main effect的用法和樣例：
例句
- No main effects are aliased with any other main effect or 2-factor interactions, but 2-factor interactions are aliased with each other.
所有的主效果都不與其他主效果相疊加，也不與兩因子交互作用相疊加，但是兩因子交互作用間互相疊加。 - The covariance analysis with verbal scores controlled reveals that verbal ability has a significant effect on ToM, but peer status has no independent effect on ToM.
控制言語后的協方差分析表明，言語對心理理論的表現有顯著主效應，但同伴地位對心理理論表現的主效應不再顯著。
