These are preliminary guidelines, subject to additions, revisions, and refinements.
The following are design guidelines for designing visitor-facing museum technologies and tools, synthesized from the collective wisdom of the museum professionals we've interacted with.
The museum experience is about the artifacts and stories behind the artifacts. If the visitor spends more time looking at their mobile device, etc. than with the artifacts, then the museum has failed.
Social interactions, conversations, etc. are part of what make the museum experience visceral. Technologies that demand the visitor's undivided, uninterrupted attention take away from that (e.g., headsets limit interaction with other visitors).
Having a hierarchical, structured content organization might make it easy for navigation, but allowing a bit of room for messiness can facilitate serendipity.
This is especially true for visitors who are new to a particular museum. Browsing is more useful than searching for most visitors, and also allows museums to suggest activities and things to see at the museum (physically or virtually).
While putting everything from the museum's collection online or on an appliance/device has its uses, what most visitors are really interested in is what they can see at the museum. Frustration ensues when a visitor sees the object online, but can't find it in the museum.