# Open-ended Evolution and a Mechanism of Novelties in Web Services

## TL;DR

This paper models web services as an ecosystem where tags evolve over time, analyzing how new tag combinations emerge and how their meanings change, reflecting open-ended evolution similar to biological systems.

## Contribution

It introduces a novel framework for analyzing the evolution of tags in social tagging systems as open-ended evolution, highlighting the self-organization of new tag combinations.

## Key findings

- Tags that change meaning over time exemplify open-ended evolution.
- The evolution of tag combinations can be quantified using the OEE index.
- Web ecosystems exhibit self-organization similar to biological ecosystems.

## Abstract

Analogous to living ecosystems in nature, web services form an artificial ecosystem consisting of many tags and their associated media, such as photographs, movies, and web pages created by human users. Concerning biological ecosystems, we regard tag as a species and human as a hidden environmental resource. We subsequently analyze the evolution of the web services, in particular social tagging systems, with respect to the self-organization of new tags. The evolution of new combinations of tags is analyzed as the open-ended evolution (OEE) index. The tag meaning is computed by the types of associated tags; tags that vary their meanings temporally exist. We argue that such tags are the examples of OEE.