What is a Reference Item?¶
A Reference Item is an Omeka item that relates other items in the collection to each other. Think of a Reference Item as a representation of a person, boat, house, business or other real world entity that is not actually part of your collection, but is related to items that are in your collection. Photographs, maps, documents, and objects like teacups are not Reference Items, but you can connect them together using Reference Items. Two common examples of using Reference Items follow.
Relating photos to each other¶
Suppose you have three photographs of a woman in your collection. Digital scans of the photographs are part
of your collection, but of course, the actual flesh and blood woman is not.
To relate these photos to each other, like you would do by putting them on the same page in a scrapbook, you could:
- Create a Reference Item as a representation of the actual woman
- Add a depicts relationship from each photo to the Reference Item
The Digital Archive would then know that the three image items are photographs of the woman. When you view one of the photos, or view the Reference Item, you'll see all three photos, plus the metadata for the Reference Item, as shown below.
As you can see from the example above, Reference Item 13575 has very little metadata, perhaps because that's all you know about the woman. Later, if you get more information about her, you can type it into the Description field or attach it to the item as a PDF file. What's important to understand is that it does not matter how little or how much metadata a Reference Item has because its primary purpose is to connect other items together. Conveying information is important, but secondary.
Relating reference items to each other¶
To extend the previous example, suppose you have pictures of Mary Ann's sisters, brother, and mother, but not one of her father. You could:
- Create a Reference Item for each sibling and for the each parent
- Add a depicts relationship from each photo to its corresponding Reference Item
- Skip the step above for dad because you don't have a picture of him
- Add a child of relationship from each sibling Reference Item to each parent Reference Item
The Digital Archive would then know enough to automatically produce the search results shown below when you view item 13575 for Mary Ann Carroll. You would see similar results when viewing any of the related items.
Four of the Reference items shown above have a manila colored matte around the image to indicate that the photo is the cover image for the Reference item. Item 13772 is also a Reference item, but it has no cover image.
As you can see, Reference Items are simple, but powerful. If you have not done so already, be sure to learn about the Archive Relational Model to understand relationships in general.
Illustrating the benefits of Reference Items
Using the example above, suppose we knew only that Mary Ann was born in 1835. You might include this information in the metadata for each of the three photographs. But later you learn additional interesting information about her such as when she died, or perhaps where she attended school. You could add this as metadata to each of the items for the three photographs, but you would be duplicating information and, in this case, tripling the amount of work.
Adding a Reference Item provides a central place to record metadata about Mary Ann, avoids duplication, reduces effort, and allows you to establish relationships to items about her family or to other items in your collection.
Other uses of Reference Items¶
The examples above have used direct relationships between between a photograph and a Reference Item (depicts relationship), and between two Reference Items (child of relationship.) The Digital Archive also automatically derives indirect, genealogical, and creator relationships from the direct relationships between Reference Items and other items.
How to create a Reference Item¶
Creating a Reference Item is easy:
- Follow the steps to add a new item
Referencefrom the Type field's dropdown list
- Choose an appropriate Subject such as
To add a relationship between a Reference Item and another item, see Add a relationship to an Item
Cover images for Reference Items¶
The Cover Image feature allows you to use the image for one item as the representative image for a Reference Item, but without attaching the image to the Reference Item. In the example immediately above, the Reference Items for the siblings, and for Rachel Foster Carroll, are all using cover images. The Reference Item for John Carroll has no image because no photograph is available for him.
You can also use a cover image when you create an item set.
In the first screenshot at the top of this page, the three photographs of Mary Ann Carroll are not Reference Items, and therefore they don't use cover images. In both examples, you can easily tell which items are Reference Items and which are not: The thumbnail for a Reference Item has a blue double border.
A Reference Item should not have an image attached to it, but it can have a PDF
The Digital Archive does not enforce this guideline, but it is a best practice because attaching an image to a Reference Item is inconsistent with the Archive Relational Model which uses the depicts relationship to associate a Reference Item with all of its images.
What a cover image looks like¶
The cover image appears in the upper left corner of the Reference Item’s page as though it were attached with a paperclip to a manila folder containing the reference information. This feature gives some "life" to the Reference Item's page so that you see the person, not just the PDF file. The cover image also appears as the thumbnail for Reference Items that do not have a PDF file attached to them such as the ones in the second example above.
In search results, a cover image appears with a manila colored matte around the image to help
distinguish its reference item from the item for the image itself. In the example below,
image 16193 on the left is the cover image for Reference item 15143.
Setting a cover image¶
To set the cover image for an item:
- Edit the item
- Choose the Cover Image tab
- In the Item field, enter the Identifier number of the item containing the image
- Click the Save Changes button
In the screenshots below, the left side shows the Cover Image tab for item 13579 which appears in the example above. The number 11562 has been entered into the tab's Item field. The right side is the item page for item 11562. This illustrates how the image from item 11562 is being used as the cover for item 13579.
There is a known problem where sometimes a newly added cover image does not display as an item's thumbnail image. If this occurs, simply edit the item and save it again without making any changes. This second save should cause the thumbnail to appear.