目次 and 索引: Chapters and specific entries
Compare choosing a chapter through a table of contents with locating a term or name through an index. Identify the information wanted without imposing a required arrangement or position in the book.
A table of contents guides chapter selection
目次 means table of contents. The examples show using it to choose a chapter and adding a detailed table of contents to a long report.
「目次を見て読みたい章を先に開いた。」 (I looked at the table of contents and opened the chapter I wanted to read first.) The reader opened the desired chapter first after looking at the table of contents. Opening a chapter does not report finishing the entire book.
An index locates a term or name
索引 means index. Its examples concern looking up an unfamiliar term and finding the pages where a person appears.
「人名索引を見れば登場するページが分かる。」 (The name index shows the pages where each person appears.) This states how to locate pages where a name appears. The index alone does not establish an understanding of what that person did.
Match the aid to the information being sought
Distinguish wanting an overview of chapters from wanting the location of a particular term or name. The detailed report contents and the book's name index belong to their separate examples.
Do not add a required alphabetical order or a fixed front-or-back location to either definition. The stated contrast is chapter structure versus locating a specific entry.
Which functions of 目次 and 索引 matter when viewing chapter structure or finding pages for a particular term or name?
Show the answer and why
The table of contents guides selection through the chapter structure. The index locates entries for a term or name. Using either aid alone does not establish that the whole book or a person's actions have been understood.