The proficiency results are generally reported separately for the four measured scales – prose literacy, document literacy, numeracy, and problem solving.
Given the comparative nature of IALSS, every effort was made to establish the validity, reliability, comparability and interpretability of estimates, and to control and quantify errors that might interfere with or bias interpretation. Notes to figures and tables are used to alert readers whenever errors might affect interpretation.
The data presented in this report are estimated from representative but complex samples of adults in Canada. Additionally, there is a degree of error associated with the measurement of skills because they are estimated on the basis of responses to samples of test items. In the report’s data tables, standard errors, in parenthesis next to the actual estimates, express the degree of uncertainty associated with both sampling and measurement errors.
When comparing 2003 IALSS results for Canada to either 2003 data for other countries or to the 1994 IALS, it is necessary to use a sub-sample of the IALSS. On one hand, the international comparisons need to be restricted to the 16 to 65 age group, since Canada is the only country that collected data for the over 65 population. On the other hand, the comparisons to the 1994 IALS need to be restricted to the provinces since the northern territories were not part of the 1994 survey. Each of these sub-samples of the 2003 IALSS displays somewhat different proficiency profiles, which needs to be kept in mind.