15 papers · ranked by Valyu relevance
Mohamed Elfil, Ahmed Negida
Clinical research usually involves patients with a certain disease or a condition. The generalizability of clinical research findings is based on multiple factors related to the internal and external validity of the research methods. The main methodological issue that influences the generalizability of clinical…
Stephen Tyrer, Bob Heyman
Surveys of people's opinions are fraught with difficulties. It is easier to obtain information from those who respond to text messages or to emails than to attempt to obtain a representative sample. Samples of the population that are selected non-randomly in this way are termed convenience samples as they are easy to…
Michelle C Kondo, Kent DW Bream, Frances K Barg, Charles C Branas
Background Nonrandom sampling of populations in developing nations has limitations and can inaccurately estimate health phenomena, especially among hard-to-reach populations such as rural residents. However, random sampling of rural populations in developing nations can be challenged by incomplete enumeration of the…
Matias López
The literature frequently recommends purposive sampling of elites based on the assumptions that random sampling negatively affects the response rate and that it induces bias. I test these assumptions drawing on metadata from 282 samples of political, economic, and social elites, and on microdata from 2,658 elites.…
Célia Landmann Szwarcwald
This article aimed to present an overview of national health surveys, sampling techniques, and components of statistical analysis of data collected using complex sampling designs. Briefly, surveys aimed at assessing the nutritional status of Brazilians and maternal and child health care were described. Surveys aimed at…
Carrie R. Howell, Wei Su, Ariann F. Nassel, April A. Agne + 1 more
Background Most studies among Hispanics have focused on individual risk factors of obesity, with less attention on interpersonal, community and environmental determinants. Conducting community based surveys to study these determinants must ensure representativeness of disparate populations. We describe the use of a…
Hiroyuki Kuwahara, Xin Gao, Can Alkan
Reservoir sampling sequentially reads a streaming file and randomly samples k elements with the equal probability from the population of unknown size n. Waterman developed a direct approach of reservoir sampling called Algorithm R in the 1970s (). Algorithm R first places the first k elements in the selection set…
Sebahat Gok, Robert L. Goldstone
Interactive computer simulations are commonly used as pedagogical tools to support students’ statistical reasoning. This paper examines whether and how these simulations enable their intended effects. We begin by contrasting two theoretical frameworks-dual processes and grounded cognition-in the context of people’s…
Muhammad Azeem, Sundus Hussain, Musarrat Ijaz, Najma Salahuddin + 1 more
'Abdul Salam'] In survey sampling, systematic sampling design has attracted survey researchers in recent years due to its simplicity of use. We introduce a modified variant of systematic sampling scheme which improves the efficiency of a recently developed diagonal systematic sampling method. The suggested modification…
Kanwal Iqbal, Syed Muhammad Muslim Raza, Tahir Mahmood, Muhammad Riaz + 1 more
'Muhammad Riaz' 'Mohamed R. Abonazel'] Advancements in sensor technology have brought a revolution in data generation. Therefore, the study variable and several linearly related auxiliary variables are recorded due to cost-effectiveness and ease of recording. These auxiliary variables are commonly observed as…
Simon R. White, Laura J. Bonnett
Title: Summary The statistical concept of sampling is often given little direct attention, typically reduced to the mantra “take a random sample”. This low resource and adaptable activity demonstrates sampling and explores issues that arise due to biased sampling.
Sarra L Hedden, Robert F Woolson, Robert J Malcolm
Background A well designed randomized clinical trial rates as the highest level of evidence for a particular intervention's efficacy. Randomization, a fundamental feature of clinical trials design, is a process invoking the use of probability to assign treatment interventions to patients. In general, randomization…
Xiangke Pu, Ge Gao, Yubo Fan, Mian Wang + 1 more
Randomized response is a research method to get accurate answers to sensitive questions in structured sample survey. Simple random sampling is widely used in surveys of sensitive questions but hard to apply on large targeted populations. On the other side, more sophisticated sampling regimes and corresponding formulas…
Michel H Hof, Anita CJ Ravelli, Aeilko H Zwinderman
Background In population-based observational studies, non-participation and delayed response to the invitation to participate are complications that often arise during the recruitment of a sample. When both are not properly dealt with, the composition of the sample can be different from the desired composition.…
Maria M, Ibrahim M. Almanjahie, Muhammad Ismail, Ammara Nawaz Cheema + 1 more
'Fabio Rapallo'] Ranked set sampling is an alternative to simple random sampling, which uses the least amount of money and time. The ranked set sampling (RSS) is modified to obtain a more efficient and cost-effective estimator of population parameters. This paper aims to bring a more efficient and cost-effective design…