Thinking about news/newspaper websites and the best practice for user experience on whether to open external links in the current or a new window or tab, that is the question:
Many wise web folk suggesting opening in the same window/tab is the best practice and has been since 1999 according to Jakob Nielsen, especially with the increase in mobile usage and how those browsers handle this action.
It’s difficult area, with various schools of thought on it over the years. In principal I’d agree it’s wrong to force the user to open a new tab or window, as WebCredible and Smashing Magazine explains:
From the usability point of view the decision to enforce opening links in new windows violates one of the fundamental principles of the user interface design: users should always be in control of the interface they are interacting with.
For example if it’s a link to more information or further content from an editorial story, e.g. a local council/police page, then it’s a logical user journey to go straight to the other site, the old maxim that if we provide good sources, they will come back to us later.
But for editorial sites I would lean towards a new window for external sites if it’s in a related but not specifically relevant commercial context, e.g an event or award sponsor. Sven Lennartz in an article for Smashing Magazine adds that : “It is appropriate to enforce opening links in a new window in case: the link may interrupt an ongoing process”