We included VDP programs with data available by site or one-site programs, which raises the question of the representativeness of the sites included, both in regard to the whole VDP program and to other existing PMTCT programs.
A major concern in interpreting our data is the question of the representativeness of a 1 m² excavation area, and whether the fluctuations described above, particularly in AH V and IV, indeed indicate a shift in resource use or subsistence, or if the patterns only reflect the limitations of the excavation.
Admittedly, such impact on the local area around the site cannot be extrapolated to a regional scale, raising question of the spatial representativeness of the previous records.
29 Indeed, Hartling et al 18 reported that raters had difficulty using the NOS because of uncertainty over the meaning of certain questions (eg, representativeness of the exposed cohort, selection of non-exposed cohort) and response options (eg, 'truly' vs 'somewhat' exposed).
As with many surveys, it is possible to question the representativeness of the respondents and the generalizability of responses.
Third, one might question the representativeness of the Portuguese data, as in the 2005 6 survey only 15% of the sample smoked.
Ours results question the representativeness of the Gabonese forest concession used for central African rain forests.
Furthermore, there are no apparent reasons to question the representativeness of the participating nurses.
While the response rate to the survey was low, bringing into question the representativeness of the sample, it was in line with evidence that both electronic surveys [ 41] and physician surveys [ 42] are associated with low responses.
