A vertical text set presents information about the same topic in a variety of reading level ranges. An example of a Vertical Text Set is an article on a specific topic from the World Book Encyclopedia used in conjunction with an article on that same topic from the Encyclopedia Britannica's Macropaedia. Both articles are on the same topic, but the World Book article will have less detail and be easier to read and understand than the article in the Britannica.
Vertical Text Sets can be used to scaffold a reader to higher levels of reading.