The Crossref Curriculum

Resolution report

Resolution reports are used for DOI resolution statistics, and are useful for identifying potential problems with depositing practices or linking.

What is a resolution? When a researcher clicks on a DOI link for an article, that counts as one DOI resolution. For example, clicking on counts as one resolution to Nature. No information is captured about the user, and these numbers are not a precise measure of traffic to a member’s website, but they provide an important measure of the effectiveness of a member’s participation in Crossref.

Resolution reports are sent out by email at the beginning of each month, and include statistics about DOI resolutions from the preceding month. By default, resolution reports are sent to the Primary contact for your organization (previously known as the business contact), but we can add or change the recipient(s) as needed. We’ll send you a separate report for each DOI prefix you’re responsible for.

The report includes:

  • Resolution failure rate: the percentage of DOI resolution attempts that failed. The prefix failure rate and the overall failure rate (for all Crossref members) are also included.
  • Resolutions by month: total number of resolutions per month for the past 12 months, by prefix (count) and overall (all members).
  • Resolution stats: resolution counts for the report prefix.
  • Top ten DOIs: list of the ten DOIs with the highest number of successful resolutions for the month, and the number of times each DOI was successfully resolved.
  • Failed DOIs: a list of DOI resolution attempts that failed (i.e. resolved to a Handle error page). This list is presented as a .csv file attached to the report email and contains both the failed DOI and number of failures.
  • Resolution counts by publication title: the number of total DOI resolutions per title

Possible reasons for DOI failure

Not all DOIs included in the failed DOI .csv are legitimate DOIs (DOIs that have been deposited). Possible reasons for DOI failure include:

  • DOI has not been deposited - make sure you deposit a DOI before distributing it
  • DOI publication and deposit are out of sync - DOIs should be deposited and distributed simultaneously. If this is not possible, the gap should be hours or a day, not days or weeks.
  • User error - users sometimes make mistakes when typing or copying DOIs. If you often see failures that you think are caused by user error, review how your DOIs are displayed. Some common user errors are:
    • Confusing O an. 0, or l and 1 - this is more common for DOIs on print publications, because have to type them, rather than clicking on a link. If your DOI failures often contain DOIs with O being confused with 0, or l with 1, consider changing your DOI suffix. Long strings of letters and numbers can cause problems as well
    • DOIs ending with ‘.’ - if a viable DOI has a ‘.’ appended, it will fail to resolve. This is often caused by the DOI being linked from references that end with a ‘.’
    • DOIs with special characters instead of ‘-’ - this commonly happens when a user pastes a DOI from a PDF
    • DOIs with special characters such as <, >, #, * and + (Crossref no longer accepts deposits with special characters)
  • Linking issues: the DOI link may be incorrect. Please correct it if the link is under your control, or contact the link creator to do so.

What should I do with my resolution report?

The resolution report gives you an overview of DOI resolution traffic, and can identify problems with your DOI links. The failed DOI.csv linked to your resolution report email contains a list of all DOIs with failed resolution attempts - if a user clicks on a DOI with your DOI prefix and the DOI is not registered, it will be included on your report.

There’s a certain amount of noise with these reports (resolutions from crawlers or automated processes) but please pay attention to any DOIs with a high number of failures, or significant changes in your resolution failure rate.

Where do the resolution report statistics come from?

Resolution statistics are based on the number of DOI resolutions made through the DOI proxy server on a month-by-month basis. These statistics give an indication of the traffic generated by users clicking DOIs. CNRI (the organization that manages the DOI resolver) sends us resolution logs at the end of every month. We do our best to filter out obvious crawlers and machine activity, and use the remaining data to create your resolution report.

What do you mean by unique DOI?

The unique DOI number is the number of distinct DOIs that have been resolved. If your report lists 20 resolutions and 1 unique DOI, this means 1 DOI was resolved 20 times.

My resolution report tells me I have a high resolution failure rate - what should I do?

The ideal failure rate is 0%, but 2-3% is the norm. If you are new to Crossref, or have only deposited metadata for a small number of content items, you may have a high failure percentage (for example, 1 failure and 9 successes = 10% failure rate).

If your overall resolution failure rate is higher than around 2-4%, look closely at the .csv file of failed DOIs for your account, and make sure the DOIs listed have been registered.

This DOI is registered - why is it on my resolution report ‘failed DOI’ list?

We send you all failed resolutions from the preceding month, even if the content has been registered. If an unregistered DOI is clicked on December 5 but not registered until December 6, we count that as a resolution failure. If you find a lot of registered DOIs in your failed DOI list, you should make sure you aren’t distributing your DOIs before they have been registered.

Will a high resolution failure rate affect my membership?

It won’t affect your membership status (unless you’re truly negligent and regularly distribute DOIs without registering them) but a Crossref membership is of limited value if you don’t register your DOIs and provide quality metadata.

Troubleshooting tips for DOIs on the failed DOI list

  • Has the DOI been registered with Crossref? If not, register it with the metadata for its content item.
  • Is the DOI link available online (check with a web search)? If not, the DOI link may be incorrect
  • When was the metadata deposited? If anyone tried to use the DOI link before that date, any resolution attempts before the deposit date will have failed
  • The Handle resolver supports URL-encoded DOIs. The resolution logs sometimes misrepresent the encoded characters. As a result, some badly-encoded DOIs will appear in your resolution log as correctly-encoded DOIs. This typically happens when an already-encoded DOI is mistakenly encoded again. For example, DOI 10.5555/example would be correctly encoded as 10.5555%2Fexample (the / is encoded as %2F). If the DOI is encoded again, the % in the DOI becomes %25, making the DOI 10.5555%252Fexample. This DOI will not resolve but will appear in the failed DOI report as 10.5555%2Fexample (a valid DOI).

Learn more about the history and current state of our popular monthly resolution reports.

Last Updated: 2020 April 8 by Laura J. Wilkinson