What Will You Learn on This Page?
On this page of the research guide, you will learn:
Once you've engaged with all the content on this page, you should:
Why Do I Have Duplicate References in My Results?
Systematic reviews published by Cochrane also appear in PubMed, so even though you're only searching two databases, you'll inevitably have at least a few duplicates in the results you've exported to your citation manager. RefWorks and Zotero operate a bit differently when it comes to duplicate management.
Choose the tab in the box below that corresponds to your citation manager to learn how to deduplicate your references.
Deduplicating Your References
RefWorks can assist you in locating many duplicates. Tap the Tools button and choose Find duplicates.
First, choose how RefWorks will determine the "primary reference." That means the one that RefWorks will assume you want to keep, deleting other versions.
Choose how close a match you want RefWorks to use. I recommend "references that are similar" to catch the most duplicates.
Select the criteria upon which you want RefWorks to determine duplicates. It defaults to title, author, and year, but I would suggest using title only.
Now RefWorks will run the duplicate check. You can watch the progress in the navigation column on the left under Duplicates.
Once the duplicate check is complete, tap the green Process completed button to see your results.
RefWorks automatically selects references to delete based on the primary reference option you selected. Tap the Delete button to move the selected references to the Trash. Always double-check to be sure the references are actually duplicates before deleting them. RefWorks may not catch all the duplicates, either, so consider sorting all your references by author or title and skimming through them, or checking the titles or authors of the references you got from the Cochrane Library manually against your PubMed references.
You can view duplicates Zotero has automatically identified by selecting the Duplicate Items special collection under My Library.
In Duplicate Items, you'll see multiple copies of each reference. Zotero allows you to merge references, retaining the most useful information in each field. To merge references, select one of the items in center pane. Zotero will automatically co-select anything it perceives as a duplicate.
In the details pane, Zotero will ask you to choose a "master item." Pick the one that has the most complete and useful details. Confirm the items are actually duplicates before merging them!
For fields where duplicates differ, tap the flowchart icon to the right of the field to choose which reference's details to use for that field only.
Once you've made all desired modifications, tap the Merge items banner at the top of the details pane.
When you merge references, the merged version will appear in all collections in which any of the original (pre-merged) references appear. This means if you have a PubMed and a Cochrane collection, the reference will still appear in both, even though there is now only one copy of that reference.
What's Next?
Have you:
Then you're ready to move on to the next page, Screening References with Rayyan!
