Successful long-term learning does not happen in the classroom, according to a recent study.

Researchers at Royal Holloway, University of London successful long-term learning happens after classroom teaching.

"Teachers have long suspected that proper rest is critical for successful learning. Our research provides some experimental support for this notion," researcher Kathy Rastle said in a statement. "Participants in our experiments were able to identify the hidden rule shortly after learning. However, it was not until they were tested a week after training that participants were able to use that rule to understand a totally new word from the fictional language when it was presented in a sentence."

For the study, academics from the Department of Psychology at Royal Holloway taught a group of people new words from a fictional language, which unknown to them, was characterized by a rule relating the new words to one another.

They found that although learners became aware of the rule within the new language shortly after being taught it, they were unable to apply it to understanding new, untrained words until after a period of rest.

"This result shows that the key processes that underpin long-term learning of general knowledge arise outside of the classroom, sometime after learning, and may be associated with brain processes that arise during sleep," Rastle said.

They also found that participants needed time to consolidate this rule-based knowledge before being introduced to new words that did not follow the rule. If the exceptions were introduced during the initial vocabulary learning session, learners were unable to develop an understanding of the general rule.

Researchers said their findings, which are detailed in the journal Cognitive Psychology, have important implications for language teaching in the classroom.