This study shows that residual variation can cause problems related to scaling in exponential random graph models (ERGM). Residual variation is likely to exist when there are unmeasured variables in a model--even those uncorrelated with other predictors--or when the logistic form of the model is inappropriate. As a consequence, coefficients cannot…

Recruiting participants through gatekeepers has been widely discussed in qualitative research. However, when a sampling frame is not available, surveying through gatekeepers can also be important for quantitative studies. We used three sampling methods to survey guardians of University students: (a) a gatekeeper variant of the time-space sampling,…

Including all children in large-scale educational studies is a pressing concern. Omitting certain types of children from studies can lead to skewed findings that promote inaccuracies about learning levels or educational quality. Increasingly, assessments are a method for investigating the quality of education systems, but national assessments are…

National average happiness and the difference in happiness between women and men are positively correlated in European countries. This study focuses on this cross-country relationship and tests (1) whether, after controlling for socio-economic factors, the correlation is attributed to their direct relationship, or, alternatively, explained by the…