This general pattern wherein western provinces score above the Canadian average, central Canada at the average and eastern provinces below the average was also observed in both the 1989 survey of Literacy Skills Used in Daily Activities (LSUDA) and the 1994 IALS. The IALSS 2003 shows that this same east to west pattern also holds for the territories. However, there are exceptions to this generalization, most notably Nova Scotia and Prince Edward Island.
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A note on statistical comparisons
The average proficiency values were computed from the scores of random samples of respondents from each jurisdiction across Canada and not from the entire population in each jurisdiction. Consequently it cannot be said with certainty that a sample average has the same value as a population average that would have been obtained had all residents been assessed. Additionally, a degree of error is associated with the scores describing a respondent’s proficiency as these scores are estimates based on responses to a sample of test items. A statistic, called the standard error, is used to express the degree of uncertainty associated with the sample error and the measurement error of the test. The standard error can be used to construct confidence intervals, which allow one to make inferences about the population mean scores and distributions in a manner that reflects the uncertainty associated with the sample estimates. A 95 percent confidence interval is used in this report and represents a range of plus or minus about two standard errors around the sample average. Using this confidence interval, it can be inferred that the population mean scores or proportions would lie within this confidence interval in 95 out of 100 replications of the measurement, using different samples randomly drawn from the same population.
When comparing scores among countries, provinces, territories or population subgroups, the degree of error in each average score should be considered in order to determine if the averages really are different from each other. Standard errors and confidence intervals may be used as the basis for performing these comparative statistical tests. Such tests can identify, with a known probability, whether there are actual differences in the populations being compared.
For example, when an observed difference is significant at the 0.05 level, it implies that the probability is less than 0.05 that the observed difference could have occurred because of sampling and measurement error. When comparing jurisdictions, extensive use is made of this type of test to reduce the likelihood that any spurious differences due to sampling and measurement error be interpreted as real.
Only statistically significant differences at the 0.05 level are noted in this report, unless otherwise stated. This means that the 95 percent confidence intervals for the averages being compared do not overlap. Due to rounding error, some non-overlapping confidence intervals share an upper or lower limit. All statistical differences are based on un-rounded data.
Table 1.1 groups provinces and territories with respect to how they compare to the Canadian average scores. Figures 1.1A to D indicate whether the average scores of the provinces and territories differ from one another in a statistically significant way. For each pair, across all four domains, the figures show which scores are statistically higher, lower or where the differences are not statistically significant. The provinces and territories are ranked by average score from highest to lowest across the columns and down the rows.