<u>Table 3: Factual and counterfactual scores of students in different upper secondary tracks</u>

|Reading<br>hi|PISA 2000<br>factual<br>weighted|PISA 2003<br>factual<br>weighted|PISA 200<br>counterfa<br>(no of ma|3 matched<br>ctual score<br>tched obs)|PISA 2006<br>factual<br>weighted|PISA 200<br>counterfa<br>(no of m|6 matched<br>ctual score<br>atched obs)|
|---|---|---|---|---|---|---|---|
|acevement|mean score|mean score|||mean score|||
||<br>(no of obs)|<br>(no of obs)|_Kernel_<br>_matching_|_1-1_<br>_matching_|<br>(no of obs)|_Kernel_<br>_matching_|_1-1_<br>_matching_|
||_(1)_|_(2)_|_(3)_|_(4)_|_(5)_|_(6)_|_(7)_|
|All hl|479.1|496.6|497.9|495.2|507.6|514.9|514.1|
|scoos|(3654)|(4196)|(4151)|(2528)|(5233)|(5229)|(3056)|
|ISCED 3C hl|357.6||466.7|460.5||484.3|474.4|
|scoos|(983)|-|(4010)|(926)|-|(5141)|(1090)|
|ISCED 3B hl|478.4||491.4|487.7||507.3|501.8|
|scoos|(1491)|-|(4150)|(1527)|-|(5163)|(1823)|
|ISCED 3A hl|543.4||525.6|524.9||543.0|547.0|
|scoos|(1180)|-|(4064)|(1233)|-|(5221)|(1376)|
|ISCED 3A and 3B|513.6||507.3|507.0||524.8|520.5|
|schools|(2671)|-|(4157)|(2206)|-|(5233)|(2609)|

Note: Standard errors are given in parentheses and were obtained from bootstrapping (kernel matching) or analytically (1-1 matching). * p<0.05, ** p<0.01, *** p<0.001 Not surprisingly, the counterfactual mean scores for all schools are similar to those reported earlier (see Table 2). Moreover, results for kernel matching and 1-to-1 matching are also similar. They differ slightly because of different matching methods and various number of matched control observations (provided in parentheses) but give qualitatively similar conclusions. This shows that the choice between reweighting or different matching methods has no crucial impact on final estimates.

Results are summarized in Table 4, where the estimates of score improvement are presented.<sup>2</sup> These estimates assess trends in performance for all students and across groups of students who without the reform would be in different secondary tracks. We see again overall improvement of average performance among 15-year-olds in Poland. Score improvement for all students is remarkable, at 16 to 18 points from 2000 to 2003 and around 35 to 36 points from 2000 to 2006. Crucial estimates are for the hypothetical performance improvement of 2000 in different tracks. Performance improvement for potential students of former vocational schools is simulated to be higher than 100 points from 2000 to 2003 and 120 points from 2000 to 2006. This is more than one standard deviation of PISA scores in OECD countries, which is a dramatic improvement, hardly comparable to effects of any known educational policy. Obviously, these estimates are statistically significant, supporting the hypothesis that 15-year-old students who without the reform would be placed in vocational tracks heavily benefited from the reform. However, the benefits for students in other tracks are not that visible. Students in mixed-general

> 2 The numbers presented in the third row, after the name of the comparison and matching method, are showing how these differences were calculated from the results presented in Table 3.  In each case, the difference was calculated by taking a counterfactual performance score of matched student from the 2003 or 2006 samples and subtracting from it the factual score of students tested in 2000.  Standard errors for these differences were calculated by employing the BRR method, which properly accounts for complex survey design (stratification, clustering, and response adjustments).

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