Lauren Pisani, Research Advisor with Save the Children, replied:

With an impact evaluation, you are typically trying to determine whether an intervention has had a significant effect on the treatment group compared to some kind of control or comparison group. You need a sample size that is large enough to conduct the statistical tests to determine the magnitude of the difference between the two groups, a small group of children will not be enough to come to a strong conclusion. Also, if the intervention period is short, you may not find substantial changes in children’s skills over this short time. If this is the case and you have a short time period, you could use IDELA to get a general sense of the skills that children in your program possess but it will not be an impact evaluation.

• This reply was modified 6 years ago by Fabiola Lara.