Table 2 Mean and standard deviation of the variables in countries and PISA cycles

PISA 2000

 Academic self-concept

.41

.97

− .05

1.03

.04

1.17

.09

.88

− .50

.94

–

–

 ESCS

.29

.91

.05

.093

.38

.83

.35

.79

− .82

.87

–

–

 Reading Achievement

497.92

96.20

548.52

87.51

505.37

103.10

515.86

91.80

525.82

83.55

–

–

 Valid N

4087

4744

3929

4340

4361

–

PISA 2018

 Self-concept in reading competence

.31

.94

.09

1.00

.21

1.03

.32

1.04

− .22

.92

.08

.87

 ESCS

.39

.84

.30

.79

.53

.82

.36

.89

− .52

1.02

− .36

1.09

 Reading achievement

489.06

94.92

519.94

99.58

497.39

105.97

505.44

106.44

527.33

97.90

561.03

90.34

 Valid N

6748

5376

5379

5156

5716

11,904