An ELT Glossary : Dictogloss

In a dictogloss activity  the teacher reads out a short text at normal speed and without pauses. The learners hear the text two or three times and then, working collaboratively in pairs or groups,  attempt to re-construct the text from memory as closely as possible to the original version. In the final stage, the learners compare their version with the original and identify syntactical and semantic differences, and grammatical or spelling errors

Dictogloss can be used for a number of purposes :

a) to practise/develop learners’ listening skills - for example, if the focus of the lesson was on features of connected speech, in the follow up stage the teacher might focus on why these blocked the learners' comprehension and how the actual pronunciation of the words differed from what they expected.
b) to present /reactivate a specific target language item or area - eg a structure or lexical set which would be built into the text.
c) to encourage "noticing" - whether the main aim of the activity focused on language subskills or items, the active search for things which they didn't understand or got wrong will make that subskill/item more memorable
d) to encourage collaborative learning