Visualization is never a ‘view from nowhere’: it always conceals as much as it unveils and it is important to remain critical towards it, or complement the view it provides with alternative angles.
This is an important caveat: a visualization of a database is always no more than that, and usually less; first, as thorough as the BHB may be, it does not cover all Haggadah editions ever printed. Whether it is because Haggadah editions simply didn’t leave any trace to be recorded, or because of the documenting policy of the BHB project. On top of this, the retrieval method I used dropped several Haggadot: I only took those that have a Yudilov’s Otzar HaHagadot identifier, and have an exact (settlement) level location that can be mapped. Dozens of Haggadot are only located in estimated regions, such as “Poland/Russia”, and they will not appear on the map. Finally, one should always remember that one edition that was documented in the BHB could have been printed in changing numbers of copies; records of printing therefore do not represent records of reading and usage.
To add to the dataset criticism, one should be wary of taking the visualization as a straightforward representation of the data: In both maps above, several editions published in the same place would only be represented with one pin. One edition – or Hundreds of Haggada editions – may have been printed in many of the places marked here with one pin.
This last limitation, however, can be mended by an alternative visualization: to express the number of editions over time I am using the tool
Palladio, to which one can upload geo-temporal data and explore it through a map, a timeline, and several other facets and visualization. The passage of times and the numbers tell their own story. This is what a travel through time in the BHB Haggadah record collection looks like: