***** To join INSNA, visit http://www.insna.org ***** Vlado,

Thanks for the pointer. I remain confused.

What I have done so far is (1) transform a two-mode network into a one-mode network; (2) remove loops and simplify the result, summing multiple lines; and (3) used the k-neighbors command to identify the k1 networks for two vertices. The problem, as I see it, is to (a) use the Operations>Extract from network command to extract the two k1 networks, (b) count the number of vertices in their union, (c) count the number of vertices in their intersection, and (d) compute the  Jaccard coefficient using the results of (b) and (c). But (b) and (c) are where I get hung up.

The summing up neighbors, max of neighbors and min of neighbors commands described on page 35 of the manual assume a vector, but at this point I have no vector to work with. Where does that vector come from? Also, the description in the manual suggests that these commands generate results for individual vertices. What I want to do is to compare pairs of vertices.

As you can see, I am, indeed, confused. Page 35 in the manual has failed to enlighten me. Can you give me a hand here.

John

On Sat, Jun 18, 2011 at 9:05 AM, Vladimir Batagelj wrote:

<<<-------- John McCreery-------->>>
> Dear Colleagues,
>
> The sociological problem is as follows. Two individuals sometimes work
> together on project teams. At one extreme, they always work together on
> the
> same teams; thus, the k1 neighbors in their ego networks are, except for
> each other, identical. At the other extreme, they work together only once,
> on one particular team; thus, the k1 neighbors in their ego networks
> differ.
> But how much do they differ. I am proposing to explore this issue using
> Jaccard coefficients to quantify the overlap between ego networks. I find
> myself in a situation I often encounter; I am working out a hack using
> Filemaker Pro, where my data is stored, and Pajek, which is my go-to tool
> for network analysis. I suspect that I am reinventing a wheel that already
> exists or unaware of a better approach to the basic problem—comparing the
> overlaps in pairs of networks.
>

See page 35 in the Pajek's manual.

--
Vladimir Batagelj, University of Ljubljana, FMF, Department of Mathematics