Field studies of psychologically targeted ads face threats to internal validity

Threats to Validity in Retrospective Studies

The internal validity of web-based studies

Honing and Ladinig (2008) make the assertion that while the internal validity of web-based studies may be reduced, this is offset by an increase in external validity possible when experimenters can sample a wider range of participants and experimental settings. In this paper, the issue of internal validity is more closely examined, and it is agued that there is no necessary reason why internal ...

Internal and external validity of cohort studies.

I participated with pleasure in discussions on 30 September 2011 in Warsaw during the ‘Diff erences in Health in the Polish population’ Conference, which aimed at critical assessment of fi rst baseline results from the PONS study, a pilot prospective cohort established in Poland. Th e PONS study results from the ‘Closing the Health Gap’ Report recommending an attempt to start building in Centra...

Yalom Curative Factors and Group Member Involvement: Threats to Internal Validity

Internal and Regional Threats to Nato Interests

The governments of Central Asia and the south Caucasus face a kaleidoscope of challenges as they each navigate the transition to modern, independent, and stable states. Most of these problems emanate from internal dynamics within each state that limit their ability to ensure stable and legitimate governments for the population. These are weak states characterized by repressive personalistic rul...