Web surveys potentially cost less to administer and are more convenient for participants than either telephone or paper-based surveys, but concern remains about the representativeness of the respondents to the population. This research investigates the effectiveness of using Webbased survey methods by comparing response rates and demographic characteristics of the telephone-based and web-based ...

Web Data Warehouses have been introduced to enable the analysis of integrated Web data. One of the main challenges in these systems is to deal with the volatile and dynamic nature of Web sources. In this work we address the effects of adding/removing/changing Web sources and data items to the Data Warehouse (DW) schema. By managing source evolution we mean the automatic propagation of these cha...