Are large surveys of adult literacy skills as comparable over time as we think?

Large-scale Assessments in Education

An IERI – International Educational Research Institute Journal

Table 4 Weighted linear regression of the natural logarithm of the literacy score, Canada, 1994 IALS, 2003 ALL and 2012 PIAAC data combined (Gross model—”Gross” cohort effect (with sex and age))

Variables	Total population—age-cohort (AC) gross model
	1994–2003–2012	2003–2012	1994–2003	1994–2012
	β ln(literacy score)
Sex
Male (Ref. Cat)
Female	0.011 [0.008]	0.003 [0.004]	0.017 [0.012]	0.010 [0.012]
Age group
25–34 years old (Ref. Cat)
16–24 years old	− 0.008 [0.009]	− 0.004 [0.007]	− 0.007 [0.013]	− 0.006 [0.014]
35–44 years old	− 0.017 [0.014]	− 0.034*** [0.007]	− 0.008 [0.018]	− 0.003 [0.024]
45–54 years old	− 0.056** [0.015]	− 0.073*** [0.010]	− 0.029 [0.032]	− 0.052* [0.019]
55–64 years old	− 0.113*** [0.019]	− 0.122*** [0.012]	− 0.092** [0.033]	− 0.110*** [0.030]
Cohort (birth year)
1966–1974 (Ref. Cat)
1930–1938	− 0.142^† [0.077]	–	− 0.166^† [0.085]	− 0.132 [0.080]
1939–1947	− 0.030 [0.020]	− 0.020 [0.017]	− 0.057^† [0.032]	− 0.024 [0.029]
1948–1956	0.004 [0.020]	0.016 [0.011]	− 0.020 [0.029]	0.008 [0.029]
1957–1965	− 0.016 [0.009]	− 0.007 [0.008]	− 0.020^† [0.012]	− 0.008 [0.016]
1975–1983	0.008 [0.006]	0.005 [0.006]	0.005 [0.009]	0.011 [0.010]
1984–1992	− 0.006 [0.010]	− 0.014 [0.009]	− 0.012 [0.015]	0.007 [0.013]
1993+	− 0.063*** [0.011]	− 0.067*** [0.011]	–	− 0.052*** [0.014]
Constant	5.655*** [0.009]	5.658*** [0.007]	5.655*** [0.010]	5.642*** [0.015]
Sample size (n)	41,362	38,979	20,642	25,099
Adjusted R²	0.066	0.043	0.074	0.071

***p ≤ 0.001; **p ≤ 0.01; *p ≤ 0.05; ^†p ≤ 0.1. Robust standard errors in brackets