Introduction

Like the library in Ranganathan's (1931) five laws of library science, the web is a growing organism, and the changing nature of the web is one of the themes that will be developed throughout this book. As this chapter will show, the technologies being utilized are changing, as are the sites and services available to investigate the web. Librarians need to understand the changing nature of such sites and services if they are to make use of web metrics for either relational or evaluative purposes.

Over the past 20 years the web has become a ubiquitous part of the modern world, and the development of associated tools and technologies has had a big impact on the nature of the web metric investigations that have taken place. During this period search engines have indexed large amounts of the web, and provided advanced search functionality that has enabled increasingly complex investigations of web content and hyperlink networks. The Web 2.0 revolution saw the major search engines and social media services provide application programming interfaces (APIs) so that developers could automatically interact with a website's content, enabling larger scale investigations to take place. The establishing of semantic web standards promised a web where many of people's mundane computing tasks could be completed automatically by computer programs (BernersLee, Hendler and Lassila, 2001), while the development of cookies has enabled organizations to track users both within and across websites (Turow, 2011). However, technological progress has not been smooth and uninterrupted. Search engine and API functionality has in some instances been retracted, a semantic web has not emerged as quickly as some people expected, and restrictions have been placed on cookies by the European Commission (Information Commission Office, 2012). All these changes have had an effecton the types of web metrics that can be developed: those metrics that were available yesterday may not be available tomorrow, but new ones will emerge. Understanding how the tools have changed in the past can help us to understand how they may change in the future and help us to recognize potential areas of opportunity.