The ISSP is a standardized survey cooperation project that presently is without parallel within the area of attitude research concerning the scope of social issues covered, the extent of countries involved, and the availability of time-series data. The ISSP started in the early 1980s and involves at present 48 countries distributed on six continents including all large Western OECD countries. The comparative ISSP database is in many ways truly unique: (a) data covering a substantial number of attitudinal areas has been collected annually since the start back in 1985; (b) time series data covering 20-30 years are available for a substantial number of topics; (c) at present, 48 countries are members of the ISSP; (d) for the scientific community, ISSP data is available for free; (e) each survey has a clear framework of a general character covering different topics which are theoretically grounded.

 Implemented and planned ISSP surveys
The Role of Government: 1985, 1990, 1996, 2006, 2016
Social Networks: 1986, 2001, 2017
Social Inequality: 1987, 1992, 1999, 2009, 2019
Family and Changing Gender Roles: 1988, 1994, 2002, 2012
Work Orientations: 1989, 1997, 2005, 2015
Religion: 1991, 1998, 2008, 2018
Environment: 1993, 2000, 2010
National Identity: 1995, 2003, 2013
Social Citizenship: 2004, 2014
Leisure and Sports: 2007
Health: 2011

As shown above, attitudes towards a variety of topics have been surveyed since 1985. Since 1990, replications of specific topic-surveys (i.e., modules) have been performed, which means that comparisons between countries, as well as over time are possible. Some specific data series span over (almost) thirty years (Role of Government 1985-2016; Social Networks 1986-2017; Social Inequality 1987-2019). Currently, there are seven time-series data sets where attitude change can be followed over a period of approximately twenty years or more.