The method involves the use of 3D laser scanning, as a means of measuring helmet standoff distance (distance between the inside of the helmet and the skull), and the selection of a representative sample of test subjects.
A potential flaw in this study is that we saw an unexpectedly high pregnancy rate in the test group including a large number of pregnancies before the start of the study, and therefore, to reduce any weakness in the study population, we implemented an additional bias recruitment to ensure that there was a representative sample of test users who did not achieve a pregnancy at the end of the study.
Plasma and breast milk HIV load was also measured for a representative sample of women who tested HIV positive at baseline.
The decreasing trend in the HIV prevalence estimate across the years could also be attributed to a more representative sample of pregnant women tested for HIV in our study.
By the mid-1990s Bolivia had implemented achievement tests in a representative sample of primary schools, but those tests ceased in the mid-2000s.
In the Vietnam Population AIDS Indicator Survey (VPAIS) 2005, it was estimated that 10% of women nationally and 60% of women in Hanoi were tested for HIV during ANC [24], while 86% of a nationally representative sample of rural Thai women tested for HIV at ANC [25].
We examined the association between pyrethroid pesticide exposure and ADHD in a nationally representative sample of US children, and tested whether this association differs by sex.
The work reported on in this paper rests on the assumptions that the 134 children who volunteered to participate in the tests are a representative sample of the population and that the four aforementioned tests sufficiently capture the learning abilities of the participating children.
The latest Timss study, the world's largest review of math and science achievement, involved testing a representative sample of students in each country in 2007, the first time the tests had been administered since 2003.
Instead, professors often select a representative sample of problems or topics and test the students on only those.
Indeed, further research to quantify the typologies among a representative sample of British women undergoing HPV testing and to indicate the dominance of certain typologies over others and to examine changes over time would be useful.
