Scholarship is a conversation between individuals and across the generations. And this conversation can often be mapped. We can look at who cites who in the scientific literature or we can look at who collaborates with each other. We can also look at annotations, because in this long conversation, scholars can have comments on each others' work.

This is a particularly appropriate method when it comes to Jewish texts. Many of these texts not only cite each other, but comment upon them, a sort of citation on steroids. For example, there is the Mishnah, part of the Oral Law in Judaism. Each section of Mishnah is in turn commented upon by the Gemara, and together these two things make up the Talmud. And there are medieval rabbis who in turn comment on the Talmud, as well as each other. And so on and so forth. With each text of course referencing and annotating the Bible. Ultimately, classical Jewish literature is one that is steeped in annotation and reference. It is the quintessential network.

Sefaria, is an open source database of Jewish texts and recently, Liz Shayne of UC Santa Barbara attempted to extract the relationships between the texts found there—annotations, allusions, and such—and visualize them. Unfortunately, Sefaria is very much a work-in-progress, so conclusions are likely too early to be drawn, but here is a quick visualization that Shayne performed of the complete network of more than 100,000 nodes and 87,000 links:

Liz Shayne, used with permission

Here is the meaning of the colors, along with some interpretation:

Blue – Biblical texts and commentaries on them (with the exception of Rashi). Each node is a verse or the commentary by one author on that verse. Green – Rashi’s commentaries. Each node is a single comment on a section Pink – The Gemara. Each node is a single section of a page. (Note – these first 3 make up 87% of the nodes in this graph. Rashi actually has the highest number of nodes, but none of them have very many connections) Red - Codes of Law. Each node is a single sub-section. Purple - The Mishnah. Each node is a single Mishnah. Orange - Other (Mysticism, Mussar, etc.) The graph, at least as far as we can see in this image, is made up almost entirely of blue and pink nodes and edges. So the majority of connections that Sefaria has recorded occur between Biblical verses and the commentaries, the Gemara and Biblical references and the Gemara referencing itself. Size corresponds to degree – the more connections a single node has, the larger it is. The largest blue node is the first verse of Genesis.

Again, these data are a work-in-progress, but it is fascinating to see the growth and shape of a network that connects texts from across thousands of years together. Read more about Shayne's analysis here, just another project in the rapidly burgeoning digital humanities. And if you want to play with the data yourself, download it here.