Who are those random responders on your survey? The case of the TIMSS 2015 student questionnaire

Large-scale Assessments in Education

An IERI – International Educational Research Institute Journal

Table 2 Percentage of eighth-grade students in each of covariates’ categories

Educational system	Gender: female	Gender: male	SES: 0–10 books	SES: 11–25 books	SES: 26–100 books	SES: 101–200 books	SES: > 200 books	SES: missing	Language: never/sometimes	Language: (almost) always	Language: missing	Migration: native-born parents	Migration: foreign-born parent	Migration: missing	Sample size: n
ARE	50	50	19	29	28	11	10	2	35	63	1	26	66	8	18012
AUS	51	49	11	18	26	20	20	6	7	92	2	51	38	11	10338
BHR	48	52	25	29	26	10	9	2	26	73	1	58	36	6	4918
CAN	51	49	11	21	30	18	17	3	13	85	3	53	42	5	8757
CHL	48	52	25	38	25	7	5	1	5	94	2	93	3	4	4849
ENG	51	49	17	22	28	16	15	2	5	93	2	65	29	6	4814
HKG	47	53	18	25	31	13	13	0	16	84	0	36	52	11	4155
IRN	48	52	27	33	22	8	10	0	33	67	0	95	3	2	6130
IRL	50	50	15	22	28	19	15	1	10	86	4	68	30	2	4704
ITA	49	51	16	25	25	16	18	1	11	88	1	81	17	2	4481
JPN	51	49	12	21	32	17	18	0	1	99	0	96	2	2	4745
KOR	47	53	7	7	22	25	39	0	0	100	0	98	1	0	5309
KWT	50	50	32	30	19	6	4	9	74	19	8	58	30	13	4503
NZL	51	49	14	18	29	19	17	2	7	91	2	57	36	7	8142
NOR	50	50	10	20	29	20	20	1	6	93	1	77	21	2	4697
OMN	48	52	24	33	25	9	8	2	33	66	1	76	22	2	8883
QAT	50	50	22	29	26	12	10	1	30	69	1	32	63	5	5403
SAU	51	49	37	30	19	6	7	2	27	73	1	79	15	6	3759
SGP	49	51	18	27	31	14	11	0	35	65	0	56	40	3	6116
TUR	48	52	16	35	30	11	8	1	10	90	0	95	3	2	6079
TWN	49	51	20	23	27	13	16	0	9	91	0	85	10	5	5711
USA	50	50	17	21	29	17	15	1	9	89	1	68	25	7	10221