I am new to Omeka’s Silver Plan; had used the free account for my Museum Collections Management Class. I am a little confused about Omeka’s message when selecting Physical Object as an Item Type. Since Omeka hosts Internet sites, even if an institution wants to display a photo of a 3-D actual artifact they have, and the institution follows Omeka’s advice, “An inanimate, three-dimensional object or substance. Note that digital representations of, or surrogates for, these objects should use Moving Image, Still Image, Text or one of the other types,” when would an institution select Physical Object as their Item Type Metadata, because every picture on Omeka is a digital surrogate?
This is ultimately a Dublin Core question, about the Physical Object type – the advice is just what they say, and the standard isn’t limited to online collections, which is where much of the confusion comes from.
To answer your question, it really comes down to how closely you adhere to strict interpretation of Dublin Core metadata, and how you interpret what an “Item” is in your site. One (rarely used) interpretation is to separate the Item metadata from the File metadata. In that approach, the Item might be, e.g., the Washington Monument, a Physical Object, while the File would be considered the surrogate. It’s a matter of conceptually separating the Item from the Files.
That’s rarely done, though, and is certainly not necessary to build a successful Omeka site.