Table 6 Kruskal–Wallis H test and pairwise comparison of 6 school groups across all PISA cycles

2000

Kruskal-Wallis H

24.883

11.925

5.643

8.204

Asymp. Sig

 < .001

.036

.343

.145

Pairwise Comparison of Groups (adj. sig. only)

G5-G1 (p = .002)

G5-G2 (p = .003)

G3-G1 (p = 0.30)

G3-G2 (p = .047)

G2-G5 (p = .021)

NS

NS

2003

Kruskal-Wallis H

3.675

8.425

1.899

3.034

Asymp. Sig

.597

.134

.863

.695

Pairwise Comparison of Groups (adj. sig. only)

NS

NS

NS

NS

2006

Kruskal-Wallis H

16.096

7.105

6.614

9.301

Asymp. Sig

.007

.213

.251

.098

Pairwise Comparison of Groups (adj. sig. only)

NS

NS

NS

NS

2009

Kruskal-Wallis H

5.582

8.281

8.005

1.402

3.107

Asymp. Sig

.349

.141

.156

.924

.683

Pairwise Comparison of Groups (adj. sig. only)

NS

NS

NS

NS

NS

2012

Kruskal-Wallis H

13.567

4.926

9.123

6.279

5.880

Asymp. Sig

.019

.425

.104

.280

.318

Pairwise Comparison of Groups (adj. sig. only)

G6-G4 (p = .048)

G6-G2 (p = .009)

NS

NS

NS

NS

2015

Kruskal-Wallis H

12.315

3.146

6.344

4.252

15.221

Asymp. Sig

.031

.677

.274

.514

.009

Pairwise Comparison of Groups (adj. sig. only)

G5-G2 (p = .015)

NS

NS

NS

G2-G5 (p = .002)

2018

Kruskal-Wallis H

12.631

12.959

11.989

9.726

8.516

Asymp. Sig

.027

.024

.035

.083

.130

Pairwise Comparison of Groups (adj. sig. only)

G5-G2 (p = .047)

NS

NS

NS

NS