A significant effect was found for type of outcome measure (larger effect sizes were found for official reports compared to self - reports of parents). (link.springer.com)
If an author wasn't in control of how her story ended, what types of outcomes do you think she would likely have had to endure? (parentpreviews.com)
To clarify, as per the section on Types of outcome measures above, studies that are qualitative reports of parent training programmes, with no quantitative assessment, will not be included. (cochranelibrary-wiley.com)