[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

From |
Paul Cohen <[email protected]> |

To |
[email protected] |

Subject |
st: bootstrapping from graphs |

Date |
Mon, 24 Jan 2005 22:57:00 -0800 |

Suppose I have a list of transactions between individuals --- Bill spoke to Jane, Fred called John, etc. I assume the list is not complete, it is a sample of transactions and perhaps a very sparse one. Moreover, I assume that the transactions are not independent; Bill might have called Jane because Alex called Bill. Suppose I make some inferences about the sample. For instance, I run the betweenness-centrality algorithm and infer that Bill and Jane belong to one organization whereas Fred and John belong to another. The overarching question is, how can I assess probabilities for these inferences? One thought is to bootstrap the transactions and estimate inference probabilities as the proportion of bootstrap samples in which the inference appears. As to the nonindependence of the transactions, I thought one might use a version of block bootstrap by saying, for instance, that transactions that co-occur within an interval must be resampled together.

I have searched for papers on resampling from graphs (as graphs represent relations between individuals) without success. Can someone point me in the right direction, please.

Here's a specific problem: If Bill does in fact know Fred and interact with him occasionally, but no transaction involving Bill and Fred appears in the sample, then no nonparametric bootstrap sample will include a transaction between Bill and Fred. On the other hand, if we make a parametric model of the transactions (i.e., they are modeled by a random graph) then any two individuals may be connected in a bootstrap sample. Both approaches seem wrong. Can anyone point me to literature on resampling from graphs in which all the links are not observed?

Thanks!

--Paul

__________________________________________________

Dr. Paul Cohen

Director, Center for Research on Unexpected Events

Deputy Director, Intelligent Systems Division

Information Sciences Institute

University of Southern California

310 448 9342

http://babs.cs.umass.edu/~cohen/home.html

*

* For searches and help try:

* http://www.stata.com/support/faqs/res/findit.html

* http://www.stata.com/support/statalist/faq

* http://www.ats.ucla.edu/stat/stata/

- Prev by Date:
**st: svr commands** - Next by Date:
**st: RE: get full command name without invoking the command** - Previous by thread:
**st: svr commands** - Next by thread:
**st: RE: get full command name without invoking the command** - Index(es):

© Copyright 1996–2024 StataCorp LLC | Terms of use | Privacy | Contact us | What's new | Site index |