There are conceptual and methodological limitations and variations in the findings.

There are methodological limitations and weaknesses in study designs however.

However, almost all of them have significant methodological limitations, as they rely on things like self-reported usage patterns, which are often unreliable.

Bratt also pointed out methodological limitations in previous studies on Jigsaw.

It also considers the methodological limitations of various approaches to ethnographic fieldwork, especially in relation to terminology.

Most data are derived from cross-sectional studies, with their inherent methodological limitations.

We believe that methodological limitations of the lactulose hydrogen breath test may explain the present results and account for the reported controversies.

There have been serious methodological limitations to much of the research implicating personality factors in anorexia nervosa.

The methodological limitations on a law/economics approach are essentially twofold.

All relevant studies have suffered from one or more methodological limitations that might invalidate their findings, scientists say.