What is it?
Mosaic copying is where the key points and structure of another person's work have been used as a scaffold (framework) for your own work, without acknowledging the source. It is sometimes used to copy the structure of sentences within a single paragraph (as seen in this example), but is also used to structure multiple paragraphs and themes in an essay or assignment.
Original referenced text
The shifting fortunes of war had a terrible impact, and not just on those who were killed or maimed in the fighting. When the republican General Custine's forces took the city of Mainz in the Rhineland in October 1792, local patriots created a Society of Friends of Liberty and Equality with five hundred members, adapted their own version of the 'Marseillaise', the 'Bürgerlied der Mainzer', and planted a liberty tree.
Text used with permission, from p. 182 of: McPhee, P. (2016). Liberty or death: The French revolution. Yale University Press.
Note: This reference is formatted in APA 7 style. See Re:cite for other styles.
The war had a much broader impact beyond that of the direct fighting (Smith, 2005). Groups of patriots formed their own societies honouring the ideals of the Revolution, such as the "Friends of Liberty and Equality" which was formed after the capture of Mainz in 1792 (McPhee, 2016, p. 182). This patriotism was often reflected in symbolic acts such as planting a liberty tree (Jones, 2011). The Mainz society even wrote their own version of the 'Marseillaise' (McPhee, 2011).
Plagiarism and poor scholarship
The changing fortunes of the conflict also affected those beyond the fighting. When General Custine took Mainz in October 1792, some locals formed a Liberty and Equality society and wrote their own version of the 'Marseillaise'. They even planted a liberty tree.
In this example the original words have been changed, but the thoughts of the original author have been used as a framework to write a section that mimics the original source. This is plagiarism. Also, the original source has not been cited.
It is a good idea to read widely on the topic and draw from multiple sources, synthesise those ideas, and then write about them in your own words. Remember to cite every source of those ideas. Avoid over-reliance on a single source, as this is poor scholarship and does not demonstrate your understanding of the topic.