The efficiency of memory recall can be increased to some extent by making inferences from our personal stockpile of world knowledge, and by our use of schema (plural: schemata). A schema is an organized mental structure or framework of pre-conceived ideas about the world and how it works, which we can use to make realistic inferences and assumptions about how to interpret and process information. Thus, our everyday communication consists not just of words and their meanings, but also of what is left out and mutually understood (e.g. if someone says “it is 3 o’clock”, our knowledge of the world usually allows us to know automatically whether it is 3am or 3pm). Such schemata are also applied to recalled memories, so that we can often flesh out details of a memory from just a skeleton memory of a central event or object. However, the use of schemata may also lead to memory errors as assumed or expected associated events are added that did not actually occur.