onSignals are writing devices that emphasize aspects of a text's content or structure without adding to the content of the the text. Findings are reviewed for studies of several different types of signaling devices, including: titles, headings, previews, overviews, summaries, typographical cues, recall sentences, number signals, importance indicators, and summary indicators. Most investigations have examined how the presence of signals in a text affects subsequent memory for the text. Virtually all types of signals produce better memory for information they cue in a text, whereas memory for unsignaled information often is unaffected. Less attention has been directed to signaling effects on other cognitive processes, such as attention, basic reading processes, and comprehension. It is argued that an understanding of how signals influence these processes will contribute to the application of signaling research to reading and writing instruction and to our general understanding of reading.