Final answer:
An index allows for a quick and organized way to find specific topics within a text, making research more efficient, especially in non-electronic versions of documents.
Step-by-step explanation:
The index is particularly helpful when looking for a specific topic because it is organized in a way that quickly directs you to where information can be found in the text. An index is typically found at the end of a book and is an alphabetical list of topics, names, and subjects mentioned within the text, along with the pages on which they appear. This structure allows for a quick launch into finding information; instead of reading through the entire document, you can reference the index for the specific topic you are interested in. This feature proves essential, especially in non-electronic versions of texts, where searching for terms is not as simple as hitting 'ctrl+f' as you would in a digital document. Moreover, in the context of research, using an index can help ensure that you have not overlooked any relevant information on your topic within a particular source.