Ebbinghaus: conducted distinctly modern and scientific research. Initially rapid memory decay, with some long term preservation. 1 month later still rmb 20% a. i. a. ii. Spacing: h: how much info was cram into one practice session: contribution to modern research methods, definitive, predictive explanation of ltm. Implicit memory: memory that you may not be aware you"ve acquired. Episodic memory: a memory for a specific autobiographical event, spatial/ temporal specificity: tagged with spatial and temporal context, learned in a single exposure, can be weakened by exposure to similar events. Semantic memory: memories for facts and general knowledge about the world and personal information, spatial/ temporal specificity: not tagged in time and space, can be learned in a single exposure, can be strengthened by repetition. Features of both memories: easy to communicate, can be communicated flexibly, in different formats than the one in which they were originally acquired, consciously available, metamemory: o: our knowledge of, and ability to think about, our own memories.