Some Key Locational Terms and Concepts in Network Analysis

Here is my own working list of key terms and definitions in network analysis. Several of these are also discussed in the wonderfully fun Six Degrees of Spaghetti Monsters blog site, with examples from the social network of Harry Potter. This list accompanies my tutorial on Network Analysis and Cytoscape for XML Coders and my Thalaba project post, “Spectacular Intersections of Place.”

Walk—A sequence of nodes and lines—with a beginning and end point node, Can double back on itself—may not be straight.  A walk (as well as a trail and a path) has a length, number of lines.

Trail—A walk with distinct lines—no connection (or communication or link) is used more than once, but a node can come up more than once (doubling back).

Path—All nodes and all lines are distinct—No node is connected more than once along a path. This is a direct route.

Closed Walk—begins and ends at same node (loop).
Cycle—closed walk of 3+ nodes—all lines distinct—all nodes in between the start and finish are distinct (and the start node = finish node).

Tour—closed walk using each line in the whole graph.

Connected vs. Disconnected: Is there a path between all nodes in the graph? If disconnected, we can refer to components of the graph (connected units of it).

Geodesic: shortest path between two nodes. Geodesic distance: length of the shortest path. If there’s no path between nodes, the geodesic distance is either considered infinite or undefined, since they can’t be reached.

Eccentricity (or association number): largest geodesic distance between a node and any other node

 Diameter of a graph: defined by the largest geodesic distance between two nodes.

Connectivity: Does a graph remain connected without particular nodes or lines?

Vulnerability: if a graph is easily broken at a few nodes or edges

Cutpoint and Cutset—Cutpoint= node that if removed makes multiple components (splits a unified graph) Cutset = set of nodes that maintains connectedness.

Bridge: Line (edge) critical to connectedness

Centralities of Various Kinds: A Useful Site for Telling Them Apart

Degree Centrality – The most central node has the highest number of ties to other nodes

Ego Density—a node’s ties / max number of possible ties

Closeness and Closeness Centrality: How quickly can a node interact with all the other nodes? Does the node need to rely on lots of other nodes to connect across the graph, or can it get to all these nodes relatively quickly?

Betweenness and Betweenness Centrality: Which nodes are in-between other nodes—which are necessary to control or mediate interactions?

Eigenvector Centrality: measures the influence of a node on the other nodes around it–a way of studying the relative importance of nodes to making other nodes more central

Random Walk Centrality: involves starting from any node and randomly moving about—how long it takes to traverse the network—sort of like pouring turning on a tap at one node and watching to see where the water runs.

Information and Information Centrality: Information of a path = inverse of its length. “In brief, the length of any path is directly related to the variance of transmitting a signal from one node to another; thus the information contained in this path is the reciprocal of this variance. Thus any path (and hence, each and every combined path) has an ‘information content.’” (Wasserman and Faust 194)

Clique: 3+ nodes adjacent to each other—a subset of nodes, in which no others are also adjacent to ALL the members. (Thalaba is full of cliques)

Small World: Most nodes aren’t connected to each other, but can be reached in one or two steps (strangers linked by mutual acquaintance)

Sources:

Borgatti, Stephen P. “Centrality and Network Flow.” Social Networks 27 (2005) 55–71. http://www.analytictech.com/borgatti/papers/centflow.pdf

Newman, M. E. J. “A measure of betweenness centrality based on random walks. arXiv:cond-mat/0309045v1 [cond-mat.stat-mech]  (Submitted on 1 Sep 2003).
Wasserman, Stanley and Katherine Faust. Social Network Analysis: Methods and Applications (Cambridge UP, 1994).

Digital Mitford Annual June Workshop Set: June 2, 3, and 4.

Mitford Puzzle
Mary Russell Mitford in Pieces!

Calling all our Digital Mitford editors, and inviting new people to join us! We’re hosting our second annual Digital Mitford Projects Workshops at the beautiful Pitt-Greensburg campus again, in the first week of June. (Arrive Sunday June 1, depart Thurs. June 5). Details to come. We’re likely to have the cost of the residence on campus covered, but probably can’t cover travel funds on our own (waiting to hear from a grant application…) For now, we ask our editors and new editors to look about for local funding sources…and we’ll keep you posted! (Editors, look for a more detailed e-mail to follow soon.)

Project Update: Headnotes for the Digital Mitford

We’re hard at work on the Digital Mitford…an update:

Digital Mitford

We’ve not had a blog update from the Digital Mitford in a while, but our project team has been busy! We’ve been working on grant writing and conference talks, not to mention semester and job activities, our energies diverted in many directions. We need a Coding Refresher Hangout, so project-team members, please check your e-mail and write back to let me know what upcoming Saturdays might work for this.

I’m taking a moment now to think aloud about Headnotes for the literary editions we aim to prepare this year for the Digital Mitford. We’re working on coding a test-bed of files, a cross-section of Mitford’s letters, prose fiction, and drama composed in the early 1820s. This moment is especially significant for us in representing Mitford and, effectively, for gluing together the fragments of her reputation. (Victorianists know her for her prose fiction, Our Village, while Romanticists–if they’re aware of…

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Confessing an Excess of Code. . .

Shall I confess it? I have too many projects to code! One project prompts another, and gets me involved in two more–and then I have a class to plan that involves teaching students to code–eek! Time moves too quickly and I’m engrossed in systems, sometimes most fretfully.

But the reward is a sudden glimpse of something I couldn’t see so clearly before–and the adventure of an experiment. Changing research methods is a giddy thing when you’re a researcher! For my next conference presentations I am working intently on coding places and cultures in Robert Southey’s ornate long poem Thalaba the Destroyer (1801), to demonstrate the complex interweaving of cultures here in a more quantitative way than I could before.

But I can’t seem to focus on Southey without being distracted by the Digital Mitford project–and happily so, as we’re fleshing out our Coding Guidelines, and as we’ve been compiling a working bibliography of Mitford’s published writings. Behind the scenes is Much Coding Work and much more to come: I’m writing some XSLT to extract and reshuffle our XML code, and I’m thinking more and more about Prosopography–our methods for compiling and collecting information on persons, places, events, and texts referenced in Mitford’s writings. Most interesting is how we’ll be indicating relationships between people and people, people and books, people and events, even people and fictional characters, or fictional characters to other fictional characters! The combinations are interesting to contemplate–and we could potentially generate many different networks to visualize!

The usual advice is to anticipate as much as possible in the early planning phases of a big coding project–but we simply cannot predict every kind of  relationship we’re going to find, and we need for a while to discover what these are going to be. Some are predictable: parent-child, marriage, friendship, but what about other kinds of relationships–when a character is modelled on an historic figure? We can identify who’s active and who’s passive, and when a relationship is mutual–not a problem here. It’s the characterization of relationships that I’m hoping will generate some interesting diversity as we code–and I don’t want to constrain that just yet.

Ideally I’d be able to write a simple RelaxNG schema to control all the coding of each *kind* of text we’re editing for the Mitford project, but we really can’t do that without running into problems very quickly: A schema needs to be something we can make distinct to the specific conditions of a particular text, and I’m thinking I’d like to make a general schema for a play (for example), and then show my editors how to fine-tune it for their purposes. For now we’re running with the general TEI P5 ALL schema built into <oXygen/>, and a set of coding rules. There is much fine-tuning to do, and much of this, I think, we really do have to figure out AS we code.

Speaking of which, it’s past time for me to be working on Thalaba! I’m not ready to post a visualization of this coding just yet–but watch this space. Thalaba is glorious to view in code structurally due to its elaborate interplay of lines and paratext notes, and paratexts-to-paratexts–and my goal here is to show something of its interweaving of physical and metaphysical places from distinct cultures. I’m eager to see what this looks like…so back to the tagging!

Madcap Adventures Part II: The Work Ahead

“What is now prov’d was once, only imagined.” A project team has formed, has met in person over three days (really four for those who arrived on Sunday and left Thursday), and has actually grown with new consulting editors–two excellent colleagues in the Pittsburgh area who discovered an interest in the Digital Mitford. I wanted to pinch my arm to see if I was dreaming many times last week: Collaboration is a new wonder and a new workflow. We hatched a plan together for a “Phase I” of the Digital Mitford to set expectations for ourselves. Everyone has begun learning new skills, including me!

Leading this workshop was a marathon, combining teaching with intense on-the-spot thinking and long-range planning in a compressed and charged moment. I found myself badly in need of sleep on the other side of it, and today I am taking stock of what must happen now: I review the first coded documents of my team: 11 digital surrogates of some very interesting ms letters and some partly formed autotagged texts of plays and poems that we’ve begun work on. I’ve been scrawling to-do lists and will be posting more about this on the Digital Mitford blog…but in this space I want to seize a moment to reflect on something more fundamental. Everything is changing, shifting in emphasis–in the past few weeks of planning and experiencing this workshop, I’m reorienting my way of thinking about research and teaching–my professional life’s work and work-as-life.

Since I was a student and chose to set off on an academic path, I’ve known myself to be pursuing a calling, that “my life” would be absorbed in it rather than compartmentalized from it. What I thought of my work as a young grad student has altered over time, with the compartmentalized experiences of university life: One’s teaching cannot always be an expression of one’s research, one must write committee reports, one is responsible to others who do not share one’s passions, and one retreats to one’s very real earthy garden or to one’s ball of yarn to take one’s mind away from fret and anxiety. One *is* compartmentalized–that’s life, but…I begin to think *now*–surely as a result of this collaborative adventure–that integration and concentration of one’s driving interests is a source of renewal and direction, perhaps in multiple facets that might not otherwise intersect. What am I contemplating?

My teaching will change this fall. If it doesn’t, I won’t be satisfied with it–I’ll have settled on an old, cold form disconnected from my transformative adventures of the past year. My coding projects lead me to wonder about the methods that matter for my students.  As I think about the stages involved in my project, I think about the stages students might take in researching and writing on a smaller scale. I want to engage students in processes that don’t necessarily expect them to reveal a *totality* of understanding or imply a *comprehensiveness.* It’s a familiar thing for me to scale down and “focus” assignment topics, but perhaps what I’m after now is an *expansion* from the scale of words and phrases.

A key question now: Can I bring my students closer to poetic language by asking them to annotate rather than explicate? Annotation is something I did in a freshman English course with great satisfaction, and without computer tools beyond the word processors of the early 1990s. Now there are more possibilities available for such work. Annotation assignments should *precede* explication at the very least.

A problem: 19th-c. Brit Lit: do I want to sacrifice reading and discussion time to teach XML coding? No–because I’m doing that in the DH class. What’s called for here is a digital tool in place, easy to access–ideally local, though we don’t have such a thing (yet!) Instead:

A feasible practice for my non-DH literature classes: I think I will try a collaborative annotation platform that I learned about from an extensive teaching praxis discussion in the HASTAC community. This is a remarkable project called “Rap Genius” which has been expanding far beyond the annotation and explication of rap lyrics to include texts of poems from past centuries in its “Poetry Genius” extension, and educators can upload texts and assignments here for students to work on. I was amazed to discover  several of Mitford’s short poems in this site, and I’m not really sure how they got here–though likely it’s the result of an automated incorporation of documents from Project Gutenberg or other text-based sources. What’s significant here: The ability to load clean base texts (not bad OCR or image files), and the ability for students to interact with them at the level of the language. The idea that this began as a site to archive and analyze rap lyrics interests me because of its attention to orality of poetic language, metrical patterns, rhymes, dissonance, assonance, consonance. This is worth exploring really as a kind of *lab space* to work closely with the oral/aural intricacies of poetic language.

Here’s another potentially useful site for teaching prosody, though the interface is not quite so open or expansive, but really focused on learning to mark meter and recognize poetic forms: “For Better or Verse.”   This large tutorial site is organized in stages and offers some fascinating selections–though my problem with it is the singularity of interpretation: The design of this extensive tutorial gives little room for variations in reading and emphasis–the human quirks that can’t easily be formulated in code. Yet it may offer students unfamiliar with poetic form a way to recognize structures–a game environment for learning. It’s worth a try.

I hope that digital annotation methods can help students to appreciate poetry rather than avoid close analysis, but my reorientation of literature assignments need not stop with poems–or especially the short lyric poems. Longer forms in prose or poems would be interesting to have students analyze in a digital lab environment, collaborating to investigate contexts and raise questions that might, I hope, lead to individual writing that’s more inspired by active learning rather than receptive, reflexive iteration. One of my colleagues on the Digital Mitford project teaches literature by having students write in collaborative contexts, and much of my writing here is inspired by recent conversations during our workshop.

As I engage in collaboration, I am caught up in learning and hope to share something of the sublime wonder of that experience with students. The realities of implementation and proof follow. I’m caught up in a confluence of ideas and possibilities, but my  implementation must be localized, dependent on the best interface with text and network that works for my group and our conversation. We live and work and dream in communities.

Madcap Adventures Part I: Mitford Coding Workshop

A short post but an effusive one to record an eventful and momentous day:  I absolutely loved what happened in our kickstart of the Mitford workshop today. We triumphed over inevitable odds: Of course, the demons that possess HDMI and VGA cables and ports prevented projection from my computer, but we needed it not! We sat about a round table, and everyone could see each other’s screen so we made a sort of connected chain–so people could readily follow my links through our workshop, and  we all helped each other when we got lost. One especially helpful project participant (our Rebecca Nesvet) wrote up detailed notes to send to our Google Hangouts members to fill in when they had connection troubles–so she helped to ensure that our coding circle reached out to our people with hiccup-y connections in LA, Boston, and England. We worked together and made technology work for us! And my team bravely asked questions and helped each other onward.

Our workshop materials are here, and I’m very much indebted to the WWP (Women Writers’ Project), Their excellent slides introduced me to TEI for manuscripts, and that’s where I’ve started my team. Tomorrow they all start coding their own letters–I’m so proud of our group!

Digital Mitford Site Launch!

. . .and there is much rejoicing! We now have a project site, and a seed start on our digital garden:

http://www.pitt.edu/~ebb8/DigitalMitford/

The site address will be changing in about a month as we move to a new server. For now, it’s a beginning, and you can see something of what we hope to do with the Digital Mitford project! I am very pleased with learning a new JavaScript trick–I’d never cycled images before.  You can see one editing project nearly finished on the site, for a sampling of the TEI and versioning I’ve been working on. As much as I like the ease of use of JuxtaCommons and the Versioning Machine, I would like to devise my own parallel text view, which will take some coding fun with XSLT.

Feedback on site design and project parameters is most welcome.