Crossref tests a broad sample of DOIs to ensure resolution. For each journal crawled, a sample of DOIs that equals 5% of the total DOIs for the journal up to a maximum of 50 DOIs is selected. The selected DOIs span prefixes and issues.
The results are recorded in Crawler reports, which are accessed from the Depositor Report expanded view. If a title has been crawled, the last crawl date is shown in the appropriate column. Crawled DOIs that generate errors will appear as a bold link:
Select the 'Last Crawl Date' link to view a Crawler Status Report for a title:
The Crawler Status Report lists the following:
- Total DOIs: Total number of DOI names for the title in system on last crawl date
- Checked: number of DOIs crawled
- Confirmed: crawler found both DOI and article title on response page
- Semi-confirmed: crawler found either DOI or article title on response page
- Not Confirmed: crawler did not find DOI or article title on response page
- Bad: page contains known phrases indicating article is not available (for example: article not found, no longer available)
- Login Page: crawler is prompted to log in, no article title or DOI
- Exception: indicates error in crawler code
- httpCode: resolution attempt results in error (400, 403, 404, 500, etc.)
- httpFailure: http server connection failed
Select each number to view details. Select 'Re-Crawl' and enter an email address to crawl again.