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Resources: Best Practices

Best Practices for Website Indexes | Tagging of Metadata | eBook Indexes

The following are suggestions that apply specifically to Website indexes. Additional guidelines for indexing in general are also applicable to Web indexes.

Site Navigation: The A-Z index should be clearly labeled and linked on the navigation menu of every page of the site. It can be called “Index,” “Site Index,” “A-Z Index,” “A-Z Site Index,” or “Topic Index,” and the index page itself should have the same title and heading.

Number of Pages: The index can be kept on one page or broken into multiple pages if it is long. If a majority of the letters of the alphabet require scrolling to view the letter section, then the index is long enough to consider breaking into individual letter pages.

Internal Index Navigation: Unless the index is so small that it can be viewed in its entirety on the screen with no scrolling, there should be a means of navigating the index either by hyperlinked “jump” letters of the alphabet at the top of each page or in a frame, or by having type-ahead scrolling enabled through an applet. The jump letters may be repeated at the bottom of the page, but usually a single top location suffices. “Back to top” (i.e., back to top of page) links should probably be added on pages that are lengthy and require scrolling.

Columns: Unless the index is so small that it can be viewed in its entirety on the screen with no scrolling, only a single column should be used, unlike the convention of dual-column printed indexes. Scrolling is easier when there is only a single column.

Entry Spacing: The entire index should be single-spaced to enable the browsing of more terms in a single screen view.

Entry Case: Lower-case should be used for entry topics to better distinguish them from page titles and other proper nouns.

Entry Font Color: If some index entries are not to be hyperlinked (such as main entries that have linked subentries), then a different color and perhaps also underlining should be used for the hyperlinked entries to indicate that they are links. A different visited-link color should also be used to indicate when an entry or its equivalent (double-posted variant) has been clicked on in order to visit a page.

Entry Font Size: A standard font size should be used, that is no smaller than that used in the Website's content text, so that it is easy to read. This is unlike book indexes which tend to use one-point smaller for index fonts.

Entry Length: Although the single column format supports long entries, conciseness is still important to enable quick browsing. Long entries are best left to proper nouns.

Entries to Nonstandard Pages: A convention (different color, parenthetical notes, added small graphic icon, etc.) should be used to indicate links to nonstandard pages, such as external links, password restricted pages, and non-HTML pages such as pdfs or Word documents.

Indenting: Indenting of subentries is the preferred style, with hanging indents for each subentry to allow quick browsing.

Subentry Levels: Up to three levels is acceptable. More than three is problematic, since only part of the index is visible in the screen view. A tendency to four levels indicates that a hierarchical taxonomy would be a better option than an A-Z index for the organization of topics.

Subentries, Number of: Contrary to book-indexing style, single subentries are acceptable, since multiple locators are usually not indicated for a single entry in a Web index. The number of subentries should best not exceed a screen view.

Cross-references: If a See or See also reference points to an index entry that has no subentries, then the link should be to the source page and not the other referred term in the index, to eliminate the need for an extra click within the index. If there are subentries under the referred term, then the See or See also reference should link to the preferred term within the index.

Tagging of Metadata

Tagging is a form of classification.


keyword tags They are used by crowdsourcing in Flickr for photograph archives e.g. name, place, description, date, author.

triple tags This takes 3 parts, subject:predicate:object: e.g. geotagging gives location of photographs, videos and maps, geo:lat=127.0010, and is similar to RDF (Resource Description Framework) where a subject Web resource is described by objects such as author, email and nickname using predicates URIs (schema) like name, mbox, nick so we get subject:predicate:object triplets like me, name, John Smith. RDF is stored in XML, includes cross-references and is discoverable.

hashtags This takes form of #keyword and is used in Twitter and Instagram. Words are run together with no spaces e.g. #timetoact

knowledge tags These are metadata used used to describe and reference information resources such as documents, images, relational tables or Web pages with fields as description, categorization, classification, semantics, hyperlinks and comments stored in a repository used in knowledge management. They are in the keyword tags of a Web page. Content Management Systems like Drupal, WordPress or Joomla! generate them from standard forms edited by the Web designer or generated from an information or knowledge management system. Correlations emerge between different tags forming folksonomies (taxonomies).

vocabulary A vocabulary is a list of metadata terms used to tag the objects e.g. Dublin Core Schema: Creator, Subject, Publisher etc.

taxonomy A taxonomy can be used to create cross-references and structure.

eBook Indexes

EPUB Publications 3.0 indexes

Types Chapter-like index (standard book index), Index term search (pop-up index), Index locator search (reverse index), Standalone index (indexs to other ebooks).

Context of index Context is used with content of ebook in a digital container to aid in discovery and connection to audio-visual content, maps, figures and footnotes.

Main topic explicit Make main topic (metatopic) clear.

Columns As screen is so small, only create 1 column for index.

Index heading running over the page As there are no pages, let the index heading flow over into the next page.

Keep concise As screen is small, keep terms short and phrases concise.

Navigation through index Use a hamburger icon (☰) to navigate to index top corner of page and use an alphabetical jump station at top of each index page.

Cross references Use cross references from common terms to preferred terms. Use general cross-references rather than specific then in general cross-reference list specific cross-references. Separate cross-references with semicolon. Suggest terms if user searches for a term not in index.

Location ranges and targets Jump to first page in range, or color pages in range or link to first and last page in range. Targets for indexes need to be placed with embedded terms. Chunking of text varies. Page breaks may or may not be embedded. Book may be broken into sections or paragraphs.

Subentries Use of subentries or subheadings for all headings if practical.

Metadata and semantic tagging for search Embed keyword, alternative synonyms and semantic terms for search. Include publisher metadata for discovery.

Locator link text Description of what locator links to.

Targets for search Embed targets for search.

Filtering of search Filter terms in results e.g. by figures and tables only.

Style sheet A style sheet with maximum font, readability and good contrast for hyperlinks and headings.

Flexible and reusable index Make index easily reflow if book is edited or republished elsewhere. External cross-references are to absolute live locations. Internal cross-references are relative to ebook.

Hyperlinked and tagged indexes This allows live index to be created which changes as content evolves.

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