The measure of socio-economic status in PISA: a review and some suggested improvements

Large-scale Assessments in Education

An IERI – International Educational Research Institute Journal

Table 2 “Books at home” across survey cycles.

	PISA 2000	PISA 2003	PISA 2006	PISA 2009	PISA 2012	PISA 2015	PISA 2018
How many books are there in your home?	ST37Q01	ST19Q01	ST15Q01	ST22Q01	ST28Q01	ST013Q01TA	ST013 Q01TA
None	1
1–10 books	2
11–50 books	3
51–100 books	4
101–250 books	5
251–500 books	6
More than 500 books	7	6	6	6	6	6	6
0–10 books		1	1	1	1	1	1
11–25 books		2	2	2	2	2	2
26–100 books		3	3	3	3	3	3
101–200 books		4	4	4	4	4	4
201–500 books		5	5	5	5	5	5

When scaling HOMEPOS, in PISA 2003, only two categories (up to 100, 101 and more) were used; in PISA 2006, only three categories (“0–25 books”, “26–100 books”, “More than 100 books”) were used; in PISA 2009, only four categories (“0–25 books”, “26–100 books”, “100–500”, “More than 500 books”) were used. In PISA 2012 and 2015, all categories were used; however, for the purpose of trend scaling, in PISA 2015 only four categories (“0–10 books”, “11–100 books”, “100–500”, “More than 500 books”) were used