|**Tab**|**le 5: Me**|**an Diff**|**erences **<br>_Disc_|**inNAf**<br>_overy Scho_|**KEStude**<br>_ols_|**nt Scor**<br>_Non-Dis_|**es at Di**<br>_covery Sch_|**fferent **<br>_ools_|**Schools, 20**<br>_Diffe_<br>_Discovery –_|**06 and 2008**<br>_rence:_<br>_Non-Discovery_|
|---|---|---|---|---|---|---|---|---|---|---|
|_Year_|_Subject_|_Grade_|_Mean_|_SD _|_SE _|_Mean_|_SD _|_SE _|**_Mean_**|_Sig. (2-tailed)_|
|2006|Math|5|27.90|13.19|0.69|29.26|11.12|1.19|**-1.37**|0.37|
|2006|Math|9|39.37|15.40|0.85|29.78|12.83|1.35|**9.59***|0.00|
|2006|Math|11|27.02|13.35|0.67|22.85|10.93|1.01|**4.17***|0.00|
|2006|Science|5|52.06|18.73|0.99|44.99|17.81|1.90|**7.07***|0.00|
|2006|Science|9|41.53|16.46|0.88|35.29|16.85|1.97|**6.24***|0.00|
|2006|Science|11|42.19|18.53|0.95|37.28|20.61|1.75|**4.91***|0.01|
|2006|Arabic|5|49.57|20.93|1.07|45.11|20.39|2.03|**4.45***|0.05|
|2006|Arabic|9|48.14|15.20|0.84|41.89|15.73|1.70|**6.24***|0.00|
|2006|Arabic|11|57.90|15.02|0.77|52.45|15.33|1.38|**5.45* **|0.00|
|2008|Math|5|30.52|13.49|0.76|26.67|9.64|0.95|**3.85***|0.00|
|2008|Math|9|39.49|14.86|0.83|31.84|12.81|1.38|**7.65***|0.00|
|2008|Math|11|29.90|14.79|0.79|29.67|14.18|1.24|**0.23**|0.88|
|2008|Science|5|51.47|17.03|0.97|48.70|19.76|1.97|**2.77**|0.17|
|2008|Science|9|46.88|18.43|1.03|36.87|17.21|1.89|**10.01***|0.00|
|2008|Science|11|44.49|22.62|1.20|42.52|23.60|2.07|**1.97***|0.40|
|2008|Arabic|5|54.38|22.76|1.28|47.51|22.89|2.18|**6.88***|0.01|
|2008|Arabic|9|56.66|19.84|1.07|48.47|17.58|1.86|**8.20***|0.00|
|2008<br>Source:|Arabic<br>Authors’ ca|11<br>lculations|63.95<br>based on NA|14.58<br>fKE 2006 an|0.76<br>d 2008 data|62.52|17.55|1.53|**1.44**|0.36|

<mark>Note: SD=standard deviation; SE=standard error</mark> The overall trend is that the academic advantage of Discovery Schools decreases once the data are controlled for background characteristics, however, some advantage remains for grade 9 students in most subjects in both years (with the exception of science in 2006). In sum, some evidence indicates that, on average, Discovery School students achieve higher scores in math and science relative to non-Discovery school students. Results become mixed after controlling for background characteristics, which could be due to non-Discovery school students improving over time.

**Table** **<u>6: Mean Differences with Controls, NAfKE Student Scores at Different Schools</u>**

||||_Without co_<br>|_Difference: Disco_<br>_ntrols_<br>|_very – Non-Disc_<br>_Controls for_<br>|_overy_<br>_family background_<br>|
|---|---|---|---|---|---|---|
|_Year_|_Subject_|_Grade_|_Mean_|_Sig. (2-tailed)_|_Mean_|_Sig. (2-tailed)_|
|2006|Math|5|-1.37|0.37|2.53|2.53|
|2006|Math|9|9.59*|0.00|7.58*|0.02|
|2006|Math|11|4.17*|0.00|4.74*|0.01|
|2006|Science|5|7.07*|0.00|10.83*|0.04|
|2006|Science|9|6.24*|0.00|0.88|0.78|
|2006|Science|11|4.91*|0.01|1.34|0.65|
|2006|Arabic|5|4.45*|0.05|5.62|0.33|
|2006|Arabic|9|6.24|0.00|6.60*|0.00|
|2006|Arabic|11|5.45|0.00|3.86*|0.05|
|2008|Math|5|3.85|0.00|2.96|0.17|
|2008|Math|9|7.65|0.00|6.74*|0.00|
|2008|Math|11|0.23|0.88|-1.20|0.45|
|2008|Science|5|2.77|0.17|-4.25*|0.09|
|2008|Science|9|10.01*|0.00|7.11*|0.00|
|2008|Science|11|1.97|0.40|1.91|0.43|
|2008|Arabic|5|6.88*|0.01|-3.62|0.28|
|2008|Arabic|9|8.20*|0.00|6.00*|0.01|
|2008<br>Source: Authors’ ca|Arabic<br>lculations based o|11<br>n NAfKE 2006 a|1.44<br>nd 2008 surveys|0.36|1.69|0.27|

Source: Authors’ calculations based on NAfKE 2006 and 2008 surveys <mark>Note: * Significant with at least a 10 percent confidence level</mark> 11