| Evaluation | Effect | Average Age | Observations | Experimental Evaluation | Country | Intervention |
|---|---|---|---|---|---|---|
| Borkum 2012 | -5 | Grade 4 | 20,858 | Yes | India | Schools were provided with libraries with books coded by difficulty |
| Sabarwal 2014 | -6 | Grade 4 | 14,774 | Yes | Sierra Leone | Students received 4 textbooks for core subjects |
| Allington 2010 | 14 | Grade 2 | 1,330 | Yes | United States | Students received 12 books that they selected for summer reading |
| Kim 2005 | 1 | Grade 4 | 468 | Yes | United States | 8 books were mailed to students to read during summer vacation |
Graph of Effects
This graph shows the effects of [Number of Evaluations] evaluations of [Program Type] programs. The first evaluation, [Evaluation name 1], estimated an effect of [Estimated effect Eval. 1] points (graphed with the top grey circle). Because this is an estimate, there is uncertainty about what the true effect is. But we know that the true effect will probably lie between a low value of [True effect lie between – Low value, Eval. 1] and a high value of [True effect lie between – High value, Eval. 1] (graphed with the top horizontal line). We can combine the estimates from all the evaluations and compute an average effect of [Estimated effect, Average] (graphed with the black circle). There is also uncertainty about where the true average effect is. But we know that the true average effect probably lies between [True effect lie between – Low value, Average] and [True effect lie between – High value, Average] points (graphed with the bottom horizontal line).
| Evaluation | Effects | Low Value | High Value | Weight in Average Effect (%) |
|---|---|---|---|---|
| Allington 2010 | 14 | 4 | 23 | 22 |
| Borkum 2012 | -5 | -13 | 3 | 25 |
| Kim 2005 | 1 | -6 | 7 | 29 |
| Sabarwal 2014 | -6 | -14 | 3 | 23 |
| Overall |