Challenges in web corpus construction for low-resource languages

I recently presented a paper at the third LRL Workshop (a joint LTC-ELRA-FLaReNet-META_NET workshop on “Less Resourced Languages, new technologies, new challenges and opportunities”).

Motivation

The state of the art tools of the “web as corpus” framework rely heavily on URLs obtained from search engines. Recently, this querying process became very slow or impossible to perform on a low budget.

Moreover, there are diverse and partly unknown search biases related to search engine optimization tricks and undocumented PageRank adjustments, so that diverse sources of URL seeds could at least ensure that there is not a single bias, but several ones. Last, the evolving web document structure and a shift from “web AS corpus” to “web FOR corpus” (increasing number of web pages and the necessity to use sampling methods) complete what I call the post-BootCaT world in web corpus construction.

Study: What are viable alternative data sources for lesser-known languages?

Trying to find reliable data sources for Indonesian, a country with a population of 237,424,363 of which 25.90 % are internet users (2011, official Indonesian statistics institute), I performed a case study of different kinds of URL sources and crawling strategies.

First, I classified URLs extracted …

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