Archive for the ‘MeSH’ Category

Topical Classification of Biomedical Research Papers – Details

Tuesday, January 3rd, 2012

OK, I registered both on the site and for the contest.

From the Task:

Our team has invested a significant amount of time and effort to gather a corpus of documents containing 20,000 journal articles from the PubMed Central open-access subset. Each of those documents was labeled by biomedical experts from PubMed with several MeSH subheadings that can be viewed as different contexts or topics discussed in the text. With a use of our automatic tagging algorithm, which we will describe in details after completion of the contest, we associated all the documents with the most related MeSH terms (headings). The competition data consists of information about strengths of those bonds, expressed as numerical value. Intuitively, they can be interpreted as values of a rough membership function that measures a degree in which a term is present in a given text. The task for the participants is to devise algorithms capable of accurately predicting MeSH subheadings (topics) assigned by the experts, based on the association strengths of the automatically generated tags. Each document can be labeled with several subheadings and this number is not fixed. In order to ensure that participants who are not familiar with biomedicine, and with the MeSH ontology in particular, have equal chances as domain experts, the names of concepts and topical classifications are removed from data. Those names and relations between data columns, as well as a dictionary translating decision class identifiers into MeSH subheadings, can be provided on request after completion of the challenge.

Data format: The data set is provided in a tabular form as two tab-separated values files, namely trainingData.csv (the training set) and testData.csv (the test set). They can be downloaded only after a successful registration to the competition. Each row of those data files represents a single document and, in the consecutive columns, it contains integers ranging from 0 to 1000, expressing association strengths to corresponding MeSH terms. Additionally, there is a trainingLables.txt file, whose consecutive rows correspond to entries in the training set (trainingData.csv). Each row of that file is a list of topic identifiers (integers ranging from 1 to 83), separated by commas, which can be regarded as a generalized classification of a journal article. This information is not available for the test set and has to be predicted by participants.

It is worth noting that, due to nature of the considered problem, the data sets are highly dimensional – the number of columns roughly corresponds to the MeSH ontology size. The data sets are also sparse, since usually only a small fraction of the MeSH terms is assigned to a particular document by our tagging algorithm. Finally, a large number of data columns have little (or even none) non-zero values (corresponding concepts are rarely assigned to documents). It is up to participants to decide which of them are still useful for the task.

I am looking at it as an opportunity to learn a good bit about automatic text classification and what, if any, role that topic maps can play in such a scenario.

Suggestions as well as team members are most welcome!

Topical Classification of Biomedical Research Papers

Monday, January 2nd, 2012

JRS 2012 Data Mining Competition: Topical Classification of Biomedical Research Papers

From the webpage:

JRS 2012 Data Mining Competition: Topical Classification of Biomedical Research Papers, is a special event of Joint Rough Sets Symposium (JRS 2012, http://sist.swjtu.edu.cn/JRS2012/) that will take place in Chengdu, China, August 17-20, 2012. The task is related to the problem of predicting topical classification of scientific publications in a field of biomedicine. Money prizes worth 1,500 USD will be awarded to the most successful teams. The contest is funded by the organizers of the JRS 2012 conference, Southwest Jiaotong University, with support from University of Warsaw, SYNAT project and TunedIT.

Introduction: Development of freely available biomedical databases allows users to search for documents containing highly specialized biomedical knowledge. Rapidly increasing size of scientific article meta-data and text repositories, such as MEDLINE [1] or PubMed Central (PMC) [2], emphasizes the growing need for accurate and scalable methods for automatic tagging and classification of textual data. For example, medical doctors often search through biomedical documents for information regarding diagnostics, drugs dosage and effect or possible complications resulting from specific treatments. In the queries, they use highly sophisticated terminology, that can be properly interpreted only with a use of a domain ontology, such as Medical Subject Headings (MeSH) [3]. In order to facilitate the searching process, documents in a database should be indexed with concepts from the ontology. Additionally, the search results could be grouped into clusters of documents, that correspond to meaningful topics matching different information needs. Such clusters should not necessarily be disjoint since one document may contain information related to several topics. In this data mining competition, we would like to raise both of the above mentioned problems, i.e. we are interested in identification of efficient algorithms for topical classification of biomedical research papers based on information about concepts from the MeSH ontology, that were automatically assigned by our tagging algorithm. In our opinion, this challenge may be appealing to all members of the Rough Set Community, as well as other data mining practitioners, due to its strong relations to well-founded subjects, such as generalized decision rules induction [4], feature extraction [5], soft and rough computing [6], semantic text mining [7], and scalable classification methods [8]. In order to ensure scientific value of this challenge, each of participating teams will be required to prepare a short report describing their approach. Those reports can be used for further validation of the results. Apart from prizes for top three teams, authors of selected solutions will be invited to prepare a paper for presentation at JRS 2012 special session devoted to the competition. Chosen papers will be published in the conference proceedings.

Data sets became available today.

This is one of those “praxis” opportunities for topic maps.