Fulvia Mecatti

Methodological perspectives for surveying rare and clustered population: towards a sequentially adaptive approach

Sampling a rare and clustered trait in a finite population is challenging: traditional sampling designs usually require a large sample size in order to obtain reasonably accurate estimates, resulting in a considerable investment of resources infront of the detection of a small number of cases. A notable example is the case of WHO’s tubercoulosis (TB) prevalence surveys, crucial for countries that bear a high TB burden, the prevalence of cases being still less than 1%. In the latest WHO guidelines, spatial patterns are not explicitly accounted for, with the risk of missing a large number of cases; moreover, cost and logistic constraints can pose further problems. After reviewing the methodology in use by WHO, the use of adaptive and sequential approaches is discussed as natural alternatives to overcome the limitations of the current practice. A small simulation study is presented to highlight possible advantages and limitations of these alternatives, and an integrated approach, combining both adaptive and sequential features in a single sampling strategy is discussed as a promising methodological perspective.

Rounding Non-integer Weights in Bootstrapping Non-iid Samples: Actual Problem or Harmless Practice?

The effect of the practice of rounding non-integer weights in bootstrapping complex samples from finite populations is investigated by means of an extended simulation study. The extent to which rounding can interfere with basic Bootstrap principles as well as with the formal properties of the final Bootstrap estimates are evaluated. Indications and recommendations on application of this practice are discussed.

The Point Is…to Publish?

Writing papers is an essential part of the research process. Researchers have a professional obligation of disseminating their results, making them available for others to use to enhance common scientific knowledge. Besides the fun of sharing their own ideas and views, to publish is essential in order to actually have a scientific career. Although scientific writing certainly has its own conventions and standards, I suspect there is no a unique true recipe making the trick. As a matter of fact I do not have any. However my quite long time in the academic arena has given me a pretty clear idea about how I do and do not like things done. In this paper I will be giving my personal view and rules, in the hope that sharing my own experience would do some good to others as it did for me.