What is PCI?

The Primo Central Index (PCI) is an aggregated index of hundreds of thousands of scholarly journals articles, in addition to many other resource types. You search this index when you search the "Everything" scope in Primo. The index includes articles from publishers, aggregators, and open access data sources.

Why are we switching to CDI?

The Ex Libris Central Discovery Index (CDI) is an upgraded version of PCI:

New infrastructure to support getting updates from data suppliers more quickly
Faster updates from Alma when resources are activated or de-activated
More tools for managing which content we choose to expose via Primo
Enhanced ranking algorithms
A separate database to store material relations (e.g. books and associated book reviews)

How is CDI different?

Restricted records and data

Some records are restricted such that you will only see them in your results if you are signed in. (This has always been true.) Now, some metadata within records will also be restricted. For example, an article may show up in search results for a user that is not signed-in, but the subject headings in that article will only display for users that are signed in.

Merged Records Instead of Record Groups

In PCI, records from different vendors for the same article are grouped, and one record from the group is displayed in the search results, with an option to see all records:

In CDI, instead of a group there will be a single merged record. This will be more intuitive for users. The merged record will include data elements from multiple vendor records:

Faster update cycle

New and updated records will be visible in CDI in 48 hours, instead of 1 week. Likewise, new library e-resource activations will be reflected after 48 hours, instead of 1 week. This will help minimize instances of broken links when we stop subscribing to a resource, and more quickly create View Online links when we subscribe to a resource.

Improved resource types

In PCI, there was a single facet for Audio-Visual. In CDI, these will now be separate facets (Audio, Visual). Full comparison of resource types.

Search and ranking

Ex Libris documentation on search and ranking.

Record source facet

The Record source facet is restricted to collections that are full text available. Content that is searchable only (and not full text available) is excluded from the facet.

Are there any known issues?

Duplicate records for some data suppliers

For several restricted ProQuest A&I collections, records are deliberately excluding from merging (e.g. the miscellaneous collections such as Sociological Abstracts, International Bibliography of the Social Sciences, Humanities Index). ProQuest offers the same title in different packages with different landing URLs which can create linking problems when the records are merged. There is an initiative underway to support package level linking, which will allow the records to be merged in the future.

Known gaps and issues

Harvard is keeping a local list of CDI Known Issues under investigation. Ex Libris maintains a full list of gaps and issues, and when they will be resolved.

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