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Cluster Sampling
In statistics, cluster sampling is a sampling plan used when mutually homogeneous yet internally heterogeneous groupings are evident in a statistical population. It is often used in marketing research. In this sampling plan, the total population is divided into these groups (known as clusters) and a simple random sample of the groups is selected. The elements in each cluster are then sampled. If all elements in each sampled cluster are sampled, then this is referred to as a "one-stage" cluster sampling plan. If a simple random subsample of elements is selected within each of these groups, this is referred to as a "two-stage" cluster sampling plan. A common motivation for cluster sampling is to reduce the total number of interviews and costs given the desired accuracy. For a fixed sample size, the expected random error is smaller when most of the variation in the population is present internally within the groups, and not between the groups. Cluster elemental The population wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Famine
A famine is a widespread scarcity of food caused by several possible factors, including, but not limited to war, natural disasters, crop failure, widespread poverty, an Financial crisis, economic catastrophe or government policies. This phenomenon is usually accompanied or followed by regional malnutrition, starvation, epidemic, and increased death, mortality. Every inhabited continent in the world has experienced a period of famine throughout history. During the 19th and 20th centuries, Southeast Asia, Southeast and South Asia, as well as Eastern Europe, Eastern and Central Europe, suffered the greatest number of fatalities due to famine. Deaths caused by famine declined sharply beginning in the 1970s, with numbers falling further since 2000. Since 2010, Africa has been the most affected continent in the world by famine. As of 2025, Haiti and Afghanistan are the two states with the most catastrophic and widespread states of famine, followed by Palestine (confined to Gaza Strip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Simple Random Sampling
In statistics, a simple random sample (or SRS) is a subset of individuals (a sample (statistics), sample) chosen from a larger Set (mathematics), set (a statistical population, population) in which a subset of individuals are chosen randomization, randomly, all with the same probability. It is a process of selecting a sample in a random way. In SRS, each subset of ''k'' individuals has the same probability of being chosen for the sample as any other subset of ''k'' individuals. Simple random sampling is a basic type of sampling and can be a component of other more complex sampling methods. Introduction The principle of simple random sampling is that every set with the same number of items has the same probability of being chosen. For example, suppose ''N'' college students want to get a ticket for a basketball game, but there are only ''X'' < ''N'' tickets for them, so they decide to have a fair way to see who gets to go. Then, everybody is given a number in the range from 0 to ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sampling (statistics)
In this statistics, quality assurance, and survey methodology, sampling is the selection of a subset or a statistical sample (termed sample for short) of individuals from within a population (statistics), statistical population to estimate characteristics of the whole population. The subset is meant to reflect the whole population, and statisticians attempt to collect samples that are representative of the population. Sampling has lower costs and faster data collection compared to recording data from the entire population (in many cases, collecting the whole population is impossible, like getting sizes of all stars in the universe), and thus, it can provide insights in cases where it is infeasible to measure an entire population. Each observation measures one or more properties (such as weight, location, colour or mass) of independent objects or individuals. In survey sampling, weights can be applied to the data to adjust for the sample design, particularly in stratified samplin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multistage Sampling
Multistage may refer to: * Armitage–Doll multistage model of carcinogenesis * Multistage amplifiers * Centrifugal pump, Multistage centrifugal pump * Multi-stage flash distillation * Multistage interconnection networks * Multistage rocket * Multistage sampling * Multistage testing {{dab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Simple Random Sampling
In statistics, a simple random sample (or SRS) is a subset of individuals (a sample (statistics), sample) chosen from a larger Set (mathematics), set (a statistical population, population) in which a subset of individuals are chosen randomization, randomly, all with the same probability. It is a process of selecting a sample in a random way. In SRS, each subset of ''k'' individuals has the same probability of being chosen for the sample as any other subset of ''k'' individuals. Simple random sampling is a basic type of sampling and can be a component of other more complex sampling methods. Introduction The principle of simple random sampling is that every set with the same number of items has the same probability of being chosen. For example, suppose ''N'' college students want to get a ticket for a basketball game, but there are only ''X'' < ''N'' tickets for them, so they decide to have a fair way to see who gets to go. Then, everybody is given a number in the range from 0 to ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Simple Random Sample
In statistics, a simple random sample (or SRS) is a subset of individuals (a sample) chosen from a larger set (a population) in which a subset of individuals are chosen randomly, all with the same probability. It is a process of selecting a sample in a random way. In SRS, each subset of ''k'' individuals has the same probability of being chosen for the sample as any other subset of ''k'' individuals. Simple random sampling is a basic type of sampling and can be a component of other more complex sampling methods. Introduction The principle of simple random sampling is that every set with the same number of items has the same probability of being chosen. For example, suppose ''N'' college students want to get a ticket for a basketball game, but there are only ''X'' < ''N'' tickets for them, so they decide to have a fair way to see who gets to go. Then, everybody is given a number in the range from 0 to ''N''-1, and random numbers are generated, either electronically or from a t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sampling Error
In statistics, sampling errors are incurred when the statistical characteristics of a population are estimated from a subset, or sample, of that population. Since the sample does not include all members of the population, statistics of the sample (often known as estimators), such as means and quartiles, generally differ from the statistics of the entire population (known as parameters). The difference between the sample statistic and population parameter is considered the sampling error.Sarndal, Swenson, and Wretman (1992), Model Assisted Survey Sampling, Springer-Verlag, For example, if one measures the height of a thousand individuals from a population of one million, the average height of the thousand is typically not the same as the average height of all one million people in the country. Since sampling is almost always done to estimate population parameters that are unknown, by definition exact measurement of the sampling errors will not be possible; however they can often ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Design Effect
In survey research, the design effect is a number that shows how well a sample of people may represent a larger group of people for a specific measure of interest (such as the mean). This is important when the sample comes from a sampling method that is different than just picking people using a simple random sample. The design effect is a positive real number, represented by the symbol \text. If \text = 1, then the sample was selected in a way that is just as good as if people were picked randomly. When \text > 1, then inference from the data collected is not as accurate as it could have been if people were picked randomly. When researchers use complicated methods to pick their sample, they use the design effect to check and adjust their results. It may also be used when planning a study in order to determine the sample size. Introduction In survey methodology, the design effect (generally denoted as \text, D_, or D_^2) is a measure of the expected impact of a sampling desig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intraclass Correlation
In statistics, the intraclass correlation, or the intraclass correlation coefficient (ICC), is a descriptive statistic that can be used when quantitative measurements are made on units that are organized into groups. It describes how strongly units in the same group resemble each other. While it is viewed as a type of correlation, unlike most other correlation measures, it operates on data structured as groups rather than data structured as paired observations. The ''intraclass correlation'' is commonly used to quantify the degree to which individuals with a fixed degree of relatedness (e.g. full siblings) resemble each other in terms of a quantitative trait (see heritability). Another prominent application is the assessment of consistency or reproducibility of quantitative measurements made by different observers measuring the same quantity. Early ICC definition: unbiased but complex formula The earliest work on intraclass correlations focused on the case of paired measu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World Bank
The World Bank is an international financial institution that provides loans and Grant (money), grants to the governments of Least developed countries, low- and Developing country, middle-income countries for the purposes of economic development. The World Bank is the collective name for the International Bank for Reconstruction and Development (IBRD) and International Development Association (IDA), two of five international organizations owned by the World Bank Group. It was established along with the International Monetary Fund at the 1944 Bretton Woods Conference. After a slow start, its first loan was to France in 1947. In its early years, it primarily focused on rebuilding Europe. Over time, it focused on providing loans to developing world countries. In the 1970s, the World Bank re-conceptualized its mission of facilitating development as being oriented around poverty reduction. For the last 30 years, it has included NGOs and environmental groups in its loan portfolio. Its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
