as opposed to 可以视作复合介词,意思是“这一点和…相反/这一点与…不符”,其中：as 是关系代词（不是副词）,表示“这一点”,指代上文说过的整个意思；opposed 是 oppose 的过去分词,表示“是处于相对状态”；to 是介词,意思是“比对”,后面跟名词作宾语.
如果从深层结构进行分析的话,as opposed to sth.其实是as is opposed to sth. 的省略,意思是“与这一点相对/与这一点不符”, 从某只意义上讲,oppose as to sth. 可以看作是它的主动形式. 省略后的as opposed to 是一种独立主格结构式的复合介词.
例如：
A fresh orange, please, i.e. real orange juice as opposed to orangeade or orange squash. 请来一杯鲜橙汁,也就是与橘子水或橙汁汽水相反的名副其实的橙汁.(as opposed to orangeade or orange squash 是介词短语作orange juice 的定语)
How strange are realities as opposed to illusion! 和幻想相反,现实是多么奇怪啊!（as opposed to illusion 是介词短语作对照性状语）
你提供的例句有误,似乎应该是 …encourages the student to think independently, as opposed to (缺少介词宾语), force-feeds students, and renders them capable only of spitting back predigested ideas—— …鼓励学生独立思考,与此相反,（他却）给学生强行灌输并让他们只能接受别人喂进去的无需自己消化的想法.（as opposed to sth. 是介词短语充当的插入性评注状语）