Organization System
Content in Yesterdays is organized in a three-level hierarchy of sources, collections, and images:
graph TD
Y["<strong>Yesterdays</strong>"]
Y --> S1["<strong>Source</strong><br/><em>e.g. <a href="https://yesterdays.maprva.org/browse/library-of-congress/">Library of Congress</a></em>"]
S1 --> C1["<strong>Collection</strong><br/><em>e.g. <a href="https://yesterdays.maprva.org/browse/library-of-congress/detroit-publishing-company/">Detroit Publishing Company</a></em>"]
C1 --> I1["<strong>Image</strong><br/><em>e.g. <a href="https://yesterdays.maprva.org/7134/">Monumental Church, Richmond, Va.</a></em>"]Sources
Sources represent individual institutions, e.g. Library of Congress, where we have sourced images on Yesterdays. The images in Yesterdays are from online databases provided by these institutions, or in some cases provided directly from those insitutions. You can browse the sources on Yesterdays here.
Collections
Collections are sequences of images. They cannot be nested. Each collection detail page includes a description of that collection as well as a link to that collection's original webpage, if available.
In general we do our best to import collections exactly as they are presented by the source. In some cases where
Images
Images are at the heart of Yesterdays.
Each image has its own unique ID, and is permanently accessible at https://yesterdays.maprva.org/<ID>.
This is called the image detail page, and includes the following information:
- a zoom-able view of the image
- metadata about that image from the source
- the current point and/or polygonal georeference, displayed on a map
- comments and georeferencing notes from Yesterdays users
- a list of subjects the image depicts
While most images in Yesterdays are old photographs, they also include:
These can often be georeferenced, too, even if they do not represent reality. For example, we can place an architectural sketch on the map even if the building was never built.
Availability
Availability refers to whether or not an image is eligible to be georeferenced. In some cases, images are tagged as Will Not Georeference, meaning that they cannot reasonably be placed on the map. These are presented with the Skip badge in Yesterdays.
Once an image has been georeferenced logged-in users may submit corrections, or subsequent georeferences, which take precedence over prior georeferences. In this way, the Yesterdays community can iteratively refine our georeferences.
Difficulty
Yesterdays administrators label images as Easy, Medium, or Difficult to indicate to other users what the difficulty of georeferencing will likely be. These are loose categorizations to help users estimate the time it would take to research an image and determine where it was taken.
Metadata
On the image detail page, the "Image Details" infobox presents what we know about an image from the source. This usually includes a date the image was created, and a description of the image.
When images are imported, miscellaenous metadata fields may be added to the description to lend context. In the following example, multiple fields from Library of Congress were combined into the description field in Yesterdays.
Rating
The rating in the "Image Details" infobox is an averaged rating from Yesterdays users. If you are logged in, clicking on the stars will reveal an interface for submitting your own rating for this image.