Generalizing or Generalizability is another way of saying "ecological validity". Essentially this is the extent to which findings (from a study) can be generalized (or extended) to the those in natural settings (i.e., outside the lab). In virtually all studies there is a trade-off between experimental control and generalizability, but obviously you want to have both. The more control psychologists exert in a study the less they may be able to generalize. For example, when we take people out of their natural environment and study them in the lab, we are exerting some control over them and, as a result, possibly limiting how much we can generalize the findings to all people in natural settings.