通常，选择程序效果案例研究的网站时应非常小心地选择这些标准，例如是否有证据表明程序已在现场实施，站点是否受到与程序具有相同的效果或可能掩盖其效果的更改，以及将此站点添加到所研究的网站组如何支持结果的可概括性。
Usually, sites for program effects case studies should be selected with great care for criteria such as whether there is evidence that the program has been implemented at the site, whether the site has been subjected to changes that could have the same effects as the program or that could mask its effects, and how the addition of this site to the group of sites being studied supports the generalizability of the findings.