The Cool URIs of the Irish Catholic Parish Registers website

Classes and URIs

The Irish Catholic Parish Registers (ICPR) project on the National Library of Ireland (NLI) website is constructed using three main classes of objects:

  1. Parish
  2. Reel
  3. Image

Home of the Irish Catholic Parish Register project

The URIs that reference instances of these classes (e.g. the Parish of Knocklong and Glenbrohane) are constructed according to a regular pattern:

Class URI Pattern
Parish http://registers.nli.ie/parishes/pppp, where pppp varies from 0001 to 1134.
Reel http://registers.nli.ie/registers/vtls000rrrrrr#page/1/mode/1up, where rrrrrr generally varies from 631891 to 635395 and from 639776 to 639824, with identifier 637417 falling in-between.
Image http://registers.nli.ie/pages/vtls000rrrrrr_nnn, where rrrrrr varies as above, and nnn varies from 001 to the total number of images in that reel.

Table 1. Three main classes of objects and their URIs in the ICPR project.

The patterning of the URIs used in the ICPR project qualify them as Cool URIs. Cool URIs greatly assist our mining data about the individual parishes, reels, and images – and, ultimately, our incorporating a subset of the ICPR project within Anphroiste. 1

First, let’s disregard the content of the human-readable documents associated with these URIs (e.g. the meaning contained within the home page of a given parish) and restrict ourselves to analyzing these URIs in order to describe the structure of the ICPR website, beginning with

  • counting the number of instances within these classes, and
  • determining the distribution of the number of instances of one class that are associated with a single instance of another class (e.g. the distribution of number of reels per parish, the distribution of number of images per reel, the distribution of number of images per parish, etc)

Parishes

As Table 1 indicates, the URIs that reference individual parishes include four-digit identifiers (ranging from 0001 to 1134).

Eight of the URIs in this series (containing the identifiers 0105, 0106, 0402, 0479, 0487, 0515, 0729, and 1130) are associated with no parish at all and resolve to the “404 File not Found” page. Of the remaining 1,126 URIs:

  • 44 (3.9%) are associated with parishes for which the NLI holds no digital images of their registers and resolve to a document reporting alternative sources of information (see Parishes excluded from the ICPR project)
  • 1,082 (96.1%) are associated with parishes for which the NLI holds one or more reels of images of their registers. 2
1,082 unique URIs reference different parishes in the Irish Catholic Parish Registers project.

Reels

As Table 1 indicates, the URIs that reference individual digital reels include a six-digit identifier – generally ranging from 631891 to 635395 and from 639776 to 639824. For more information on the stand-alone identifier that falls between these two ranges, see Digital Reel 637417 in the Irish Catholic Parish Registers project.

In fact, there are a few breaks within these two blocks of identifiers; the list of identifiers used in URIs that reference reels of images is:

  • 631891 to 632373 (383 IDs)
  • 632277 to 633290 (1,014 IDs)
  • 633292 to 633433 (142 IDs)
  • 633436 to 633563 (128 IDs)
  • 633565 to 635395 (1,831 IDs)
  • 637417 (1 ID)
  • 639776 to 639824 (49 IDs)
3,548 unique URIs reference different reels of images in the Irish Catholic Parish Registers project.

Parishes and Reels

The number of reels of images associated with a given parish ranges from 1 to 44 (for the parish of St. Andrew’s, Dublin city). Table 2 and Figure 1 provide the distribution of number of digital reels per parish.

Reels Parishes (n) Parishes (%)
1 235 21.7%
2 279 25.8%
3 228 21.1%
4 143 13.2%
5 72 6.7%
6 48 4.4%
7 28 2.6%
8 14 1.3%
9 8 0.7%
10 7 0.6%
11 2 0.2%
12 2 0.2%
13 2 0.2%
14 2 0.2%
15 1 0.1%
16 2 0.2%
17 1 0.1%
19 1 0.1%
20 – 29 1 0.1%
30 – 39 4 0.4%
40 – 49 2 0.2%
Total 1,082 100.0%

Table 2. Distribution of number of digital reels per parish.

Irish Catholic Parish Registers project - Distribution of number of digital reels per parish

Figure 1. Distribution of number of digital reels per parish.

On the other hand – with one exception alone – every digital reel of images is associated with one and only one parish. The one exception is the digital reel referenced by the stand-alone identifier 637417 (see above and Digital Reel 637417 in the Irish Catholic Parish Registers project, for more information).

Reels and Images

As Table 1 indicates, the URIs that reference individual digital images include a six-digit identifier for the reel and a three-digit identifier for the page number.

The number of images associated with a given digital reel ranges from 3 to 578 (for the parish of Harrington St., Dublin city) for a total of 372,756 images. 3

372,756 unique URIs reference different images in the Irish Catholic Parish Registers project.

Table 3 provides the distribution of number of images per reel.

Images per Reel Reels (n)

Reels (%)

1-50 1,032 29.1%
51-100 942 26.6%
101-150 729 20.5%
151-200 482 13.6%
201-250 196 5.5%
251-300 93 2.6%
301-350 40 1.1%
351-400 19 0.5%
401-450 9 0.3%
451-500 2 0.1%
501-550 2 0.1%
551-600 2 0.1%
Total 3,548 100.0%

Table 3. Distribution of number of digital images per reel.

Some things to do along these lines of analysis

  • Our count of 1,082 parishes in the Irish Catholic Parish Registers project is at odds with the NLI’s official figure of 1,086. Some work is required to resolve the discrepancy.
  • We should derive the distribution of number of images/parish from the parish-reel(s) and reel-images tables.

Summary

We have used the URIs that reference instances of the three main classes of the Irish Catholic Parish Register project to describe the main features of the structure of the ICPR website:

  • counting the number of instances within these classes, and
  • determining the distribution of the number of instances of one class that are associated with a single instance of another class

Let’s now examine the content of the human-readable documents associated with these URIs (e.g. the meaning contained within the home page of a given parish), beginning with the names of the Irish Catholic Parish Registers project.

 

  1. We will describe our data mining tools and techniques in more detail elsewhere.
  2. Our figure of 1,082 parishes is at odds with the NLI’s official count of 1,086 parishes for which it holds images of their registers. Some work is required to resolve the discrepancy.
  3. The source code for vtls ID=634188 has no number of images, but our inspection of the web page showed 78 images and the comment “List of inhabitants showing Christmas dues 1834, Easter dues 1835 and remembrance masses for July 27, 1835 – May 13, 1837”.