Every respondent was first given a common questionnaire seeking information about demographic characteristics and variables such as educational attainment, occupation, income, and engagement in adult learning and community activities. The respondents were then given an internationally validated psychometric3 instrument designed to measure proficiency in four domains:

• Prose literacy – the knowledge and skills needed to understand and use information from texts including editorials, news stories, brochures and instruction manuals.
• Document literacy – the knowledge and skills required to locate and use information contained in various formats, including job applications, payroll forms, transportation schedules, maps, tables and charts.
• Numeracy – the knowledge and skills required to effectively manage the mathematical demands of diverse situations.
• Problem solving – problem solving involves goal-directed thinking and action in situations for which no routine solutions exist. The problem solver has a more or less well defined goal, but it is not immediately obvious how to reach it. The incongruence of goals and admissible operators constitutes a problem. The understanding of the problem situation and its step-by-step transformation, based on planning and reasoning, constitute the process of problem solving.

The IALSS builds on its predecessor, the 1994 International Adult Literacy Survey (IALS). The IALSS numeracy scale expands the quantitative literacy domain measured in 1994 and is a broader, more inclusive measure of mathematics skills and knowledge. Problem solving is a new domain in 2003. The prose and document literacy scales used in 2003, however, are identical to those carried by the IALS in 1994. Thus, for several countries including Canada, it is now possible to examine both the current distributions of prose and document literacy and how these have evolved between 1994 and 2003.