Related Experiment Video
Updated: Jun 21, 2026

Cloud-Based Phrase Mining and Analysis of User-Defined Phrase-Category Association in Biomedical Publications
Published on: February 23, 2019
Clinical text classification under the Open and Closed Topic Assumptions.
Yutaka Sasaki1, Brian Rea, Sophia Ananiadou
1School of Computer Science, University of Manchester MIB, 131 Princess Street, Manchester, M1 7DN, UK. Yutaka.Sasaki@manchester.ac.uk
This study compares multi-topic classification in clinical versus general text. Clinical text leans towards open topic assumptions, while general text falls in the middle, differing from closed topic assumptions.
Area of Science:
- Natural Language Processing
- Computational Linguistics
- Medical Informatics
Background:
- Automatic text classification is crucial for organizing large datasets.
- Understanding multi-topic characteristics is key for accurate classification.
- Clinical text presents unique challenges compared to general text.
Purpose of the Study:
- To investigate and compare multi-topic aspects in automatic classification of clinical free text versus general text.
- To analyze text classification under the Closed Topic Assumption (CTA) and Open Topic Assumption (OTA).
Main Methods:
- Facilitated two distinct views on multi-topics: CTA and OTA.
- Conducted comparative analysis using Computational Medicine Centre (CMC) Medical NLP Challenge Data and Reuters-21578 (general text).
Main Results:
- Multi-topic assignments in CMC Medical NLP Challenge Data are strongly Open Topic Assumption (OTA)-oriented.
- General text (Reuters-21578) exhibits characteristics between the OTA and CTA spectrum.
- Clinical text demonstrates a distinct preference for open topic modeling.
Conclusions:
- Clinical free text exhibits a strong Open Topic Assumption (OTA) orientation in multi-topic classification.
- General text shows a mixed characteristic between Open Topic Assumption (OTA) and Closed Topic Assumption (CTA).
- These findings highlight the need for tailored approaches in clinical text classification.
Related Concept Videos
Classification of Illness
An illness is a response to a disease in which the person's level of functioning is changed compared with a previous level. The general classification of illness includes acute and chronic.
Acute illness is severe and...
Classification of Systems-II
Force Classification
Contact and non-contact forces are two of the most widely used categories of forces. As the name suggests, contact forces require physical contact between two objects to act upon each other. Examples of contact forces include frictional,...
Classification of Signals
A continuous-time signal holds a value at every instant in time, representing information seamlessly. In contrast, a discrete-time signal holds values only at specific moments, often denoted as x(n), where...
Classification of Leukocytes
Neutrophils are the most abundant type of granular leukocytes, comprising 50-70% of all leukocytes. They feature small, evenly distributed granules and a...
Classification of Systems-I
Homogeneity dictates that if an input x(t) is multiplied by a constant c, the output y(t) is multiplied by the same constant. Mathematically, this is expressed as: