Comparing Video Media Formats in Incoming and Existing Bibliographic Records
Innovative can configure your INN-Reach Catalog to compare video media formats as specified in the MARC 538 (System Details Note) fields in incoming and master bibliographic records once the records have been identified as potential matches.
If your INN-Reach Catalog is configured to compare MARC 538 fields, the system evaluates this field when matching on both Primary Match Fields and Secondary Match Fields. To change whether or not the system compares MARC 538 data when evaluating potential matches, your Central System Administrator must contact Innovative.
This comparison searches the MARC 538$a subfield for text that distinguishes the video format. The system normalizes the data in the subfield and determines whether one of the following default three-character text values is present:
| Format | Normalized Text |
|---|---|
| VHS | vhs |
| DVD | dvd |
| Blu-ray | blu |
If these text values are present in the MARC 538 fields of the potential matches, the text values must be the same in both records in order for the records to match. For example, the records match if both records contain "vhs", or the records do not match if one record contains "vhs" and the other contains "dvd".
If these text values are absent from one or both of the MARC 538 fields of the potential matches, the system considers the fields to match; the absence of data is treated as equivalent to the presence of matching data.
Note that this comparison uses only data from the first instance of subfield $a in each of the MARC 538 fields.
If your INN-Reach Catalog is configured to compare MARC 538 data, INN-Reach does the following:
- Determines whether the potential matches contain MARC 538$a subfields:
- If the MARC 538$a subfield is present in both records, the system continues to the next step in this evaluation.
- If the MARC 538$a subfield is absent from both records, or is present in one but not the other, go to MARC 538 data matches; the system treats the absence of the subfield as equivalent to the presence of a subfield containing matching data.
- Normalizes the MARC 538 comparison strings:
- If the strings normalize to usable data in both records, the system continues to the next step in this evaluation.
- If a string does not normalize to usable data in one or both records, the MARC 538 data matches; the absence of data is treated as equivalent to the presence of matching data.
- Determines whether the normalized 538 strings contain text that distinguishes the video format:
- If the video format text is present in both normalized 538 strings, the system continues to the next step in this evaluation.
- If the video format text is absent from one or both normalized 538 strings, the system does not need to perform any additional steps in this evaluation; the MARC 538 data matches.
- Compares the normalized 538 strings:
- If the strings match, the MARC 538 data matches.
- If the strings do not match, the MARC 538 data does not match.
Possible Outcomes of a MARC 538 Comparison
- MARC 538 Data Matches
- If the MARC 538 data matches (or is considered equivalent to a match by the system), the system stops the evaluation and proceeds as appropriate:
- If your INN-Reach System has been configured for additional evaluations (for example, title comparison), the system continues to the next evaluation of the potential matches.
- If no additional evaluations have been configured for your INN-Reach System, the system identifies the records as a match.
- MARC 538 Data Does Not Match
- If the MARC 538 data does not match, the system stops any further evaluation of the potential matches that your INN-Reach System might be configured to perform. It identifies the records as not a match.
Normalizing MARC 538$a Subfield Data
To normalize data from MARC 538$a subfields, the system:
- Makes all characters in the string lower case.
- Replaces punctuation with spaces.
- Replaces multiple spaces with a single space.
- Extracts the first three characters of the remaining string.
This normalization process can result in an empty string. If the normalization process results in a non-empty string, it is considered "usable" for the purposes of comparison.
For example:
| Example | Original Subfield Data | Normalized Subfield Data |
|---|---|---|
| 1 | n538 |aVHS. | vhs |
| 2 | n538 |aVHS format | vhs |
| 3 | n538 |aDVD, all regions; NTSC; Dolby digital 2.0. | dvd |
| 4 | n538 |aDVD ; stereo / Dolby surround ; AC-3 ; Dolby digital sound | dvd |
| 5 | n538 |aDVD EXPO; DVD 9; NTSC; all regions; Dolby digital 5.1 and mono. | dvd |
| 6 | n538 |aBlu-ray disc, widescreen (2.40:1) presentation; Dolby Digital 5.1 surround, 1080p High Definition ; (Special features: Dolby Digital stereo., 1080p High Definition). | blu |
| 7 | n538 |aRequires Blu-ray player. | req |
| 8 | n538 |aAvailable via the World Wide Web. | ava |
| 9 | n538 |aCompact disc, MP3 format. | com |
| 10 | n538 |aSystem requirements: CD/MP3 player or PC with MP3-capable software. | sys |
In the above examples:
- Examples 1 and 2 match each other as VHS format.
- Examples 3, 4, and 5 match each other as DVD format.
- Examples 6 and 7 do NOT match each other as Blu-ray format, because the format notation in Example 7 does not appear in the first three characters.
- Examples 7, 8, 9, and 10 do not normalize to the required text specifying a video format; as such, they are equivalent to an empty string. They can match any example in the table. No specified format matches with all other formats.