Natural language queries are now possible on Perseus under Philologic. Previously, Richard had implemented searching for various parts of speech in various forms. For instance, as noted in the About page for Perseus, a search for 'pos:v*roa*' will return all the instances of perfect active aorist verbs in the selected corpus. Now, a search for 'form:could-I-please-have-some-perfect-active-optatives?' will return the same results. In fact, searching for 'form:perf-act-opt', 'form:perfect-active-optative', 'form:perfection-of-action-optimizations',...
Encyclopédie: Similar Article Identification II
After doing a series of revisions as part of my last post this subject (link), I thought it might be helpful to provide an update posting. We have been interested in teasing out how the VSM handles small vs large articles and to get some sense of why various similar articles are selected. Over the weekend, I reran the vector space similarity function on 39,218 articles, taking some 29 hours. I excluded some 150 surface forms of words in a stopword list, all sequences of numbers (and roman numerals), as well as features...
Mapping Encyclopédie classes of knowledge to LDA generated topics
As was described in my previous blog entry, I've been working on comparing the results given by LDA generated topics with the classes of knowledge identified by the philosophes in the Encyclopédie. My initial experiment was to try to see if out of 5000 articles belonging to 100 classes of knowledge, with 50 articles per class, I would find those 100 topics using an LDA topic modeler. My conclusion was that it didn't find all of them, but still found quite a few. Since then, I have played a bit more with this dataset and...
Index Design Notes 1: PhiloLogic Index Overview
I've been playing around with some perl code in response to several questions about the structure of PhiloLogic's main word index--I'll post it soon, but in the meantime, I thought I'd try to give a conceptual overview of how the index works. As you may know, PhiloLogic's main index data structure is a hash table supporting O(1) lookup of any given keyword. You may also know that PhiloLogic only stores integers in the index: all text objects are represented as hierarchical addresses, something like a normalized, fixed-width...
Encyclopédie: Similar Article Identification
The Vector Space Model (VSM) is a classic approach to information retrieval. We integrated this as a standard function in PhiloMine and have used it for a number of specific research projects, such as identifying borrowings from the Dictionnaire de Trévoux in the Encyclopédie, which is described in our forthcoming paper "Plundering Philosophers" and related talks[1]. While originally developed by Gerard Salton[2] in 1975 as a model for classic information retrieval, where a user submits a query and gets results in an ranked...
