Researches on multiple external representations(MERs) in mathematics learning had become flourishing topics in the last two decades.

The Teaching Research on Optimizing the Learning of Multi-representations of Analytical Geometry Concepts;

Ever since 1990s, research on multi-representations has become a hot topic in fields such as cognitive science, education with integration of ICT in education.

Based on knowledge of brain-recognition network,strategic network and affective network in addition to the essence of e-media,there are three principles of UDL:(1) multiple means of representation—the "what" of learning,(2) multiple means of expression—the "how" of learning,and(3) multiple means of engagement—the "why" of learning.

Applying method of eye movement analysis,the effect of external feature changing on face identification is studied.

The exploration of the use of metarepresentation will facilitate the development of metarepresentation theories and simultaneously promote the transition of researches into metarepresentation from the approach of philosophy and psychology to that of pragmatics.