What is a Database? - Activity 1

Introduction | Prep | Presentation | Activity 1 | Activity 2

Compare library catalogs (10 minutes)

One of the searchable interfaces you’ll use most often is your library’s catalog. All scholars need to adjust to different catalog interfaces throughout their career.

Take a few minutes to explore some library catalogs.

• British Library (explore.bl.uk Links to an external site.) or Purdue (lib.purdue.edu Links to an external site.) - these are both on the same platform as Harvard’s HOLLIS
• Boston Public Library (BPL, bpl.org Links to an external site.) or New York Public Library (NYPL, nypl.org Links to an external site.) - these are on platforms that are different from Harvard’s HOLLIS
• Choose your own! Pick any library catalog you like.

Tip: Try different test searches. For example, search for a citation you already know, and for a topic you want to explore. Play around with the filter and advanced search options. Try to find the options for accessing materials. How do the variety of options compare to your institution’s library catalog?

Is it a catalog or a discovery layer? (5 minutes)

Take your best guess: is the catalog you explored:

• A traditional library catalog

  Books, journals, objects, and archival collections held by the library. Sometimes called the OPAC.

• A library discovery layer 

  A large all-in-one search tool that combines an articles index with the library catalog

Most academic libraries in the US offer a catalog search that pulls in a huge amount of data from other sources. This is called a “discovery layer,” and it typically provides article-level searching.

Discovery layers across different libraries often look and behave in similar ways. In part, this is because a handful of companies produce the software that runs these systems.

Those companies also compile the article citations. The discovery layer can feel like a cross-database search, but that is not exactly what is happening. Read Harvard’s response to this commonly asked question.

Understand what a discovery layer searches (15 minutes)

Explore our What HOLLIS Searches infographic to better understand how information flows into a discovery layer’s search function.

This infographic visualizes how citations and other data flow into Harvard’s library discovery system.

The leaky spots indicate where data is incompatible, and the valves indicate where only a portion of the data is shared. Some of the labels in the illustration are specific to Harvard Library’s catalog, but the types of information and their sources are typical of the discovery layer for any library.

Download the "What HOLLIS Searches" infographic (20MB)

Additional download options:

Medium-resolution PDF version (31 MB) Links to an external site.

High-resolution PDF version (239 MB) Links to an external site.

Editable vector files are available from the facilitator’s page for this module Links to an external site..

Audio tour:

Access the "What HOLLIS Searches" Audio Tour in Panopto. Links to an external site.

Image description:

The infographic depicts a system of tanks connected by pipes that all feed into a large tank labeled “Catalog & Articles.”

On one side, a cluster of small tanks labeled library catalog, image catalog, Finding Aids, third-party vendor data, and ReCAP consortium catalog all feed into a medium-sized tank labeled Library Catalog. The Library Catalog feeds into the large Catalog & Articles tank.

On the other side, there are three tanks that feed into the Catalog & Articles tank. These three tanks are a large Publishers tank, medium Scholarly Indexes & Library Vendors tank, and a much smaller Open Access Projects tank. The Publishers tank is fed by pipes labeled Full Text and Brief Citations. The Scholarly Indexes tank is fed by pipes labeled Full Text, Brief Citations, and Detailed Citations. The Open Access Projects tank is fed by pipes labeled books, articles, and digital collections.

Above the Publishers and Scholarly Indexes tank are valves with gauges from 0 to 100%. The valves represent licensing agreements, which control how much information is shared. On the pipes that flow out of Publishers, Scholarly Indexes, and Open Access Projects are on/off valves. The on/off valves represent local decisions about which information bundles to include in the discovery layer.

Throughout the system there are leaky connections that represent data compatibility issues. A key explains that this is where information gets lost when it is not formatted in a way HOLLIS can understand.

Four signs on the sides of the infographic explain the types of information identified by the pipe and tank labels. Catalog records are structured descriptions of library materials. Finding aids are detailed inventories of archival collections. Citations are descriptive metadata about an item, similar to catalog records. A brief citation may have only publication information such as author, title, publisher, and date, while a detailed citation may include an abstract, topical subjects, and information such as how often the item has been cited. Full text refers to full-text metadata. If full-text metadata is present, your search terms will match to any words that appear in the publication.

Note: find a list of the types of records that show up in HOLLIS's search scopes on the "Choose where to Search Page" of the HOLLIS User Guide.

Introduction | Prep | Presentation | Activity 1 | Activity 2