Survey, target population

The target population for a survey is that set of elements about which the data will be used to make inferences. The target population for the national radon survey will be all occupied residential housing units in the United States which are used as primary residences. This will include both single and multi-family housing units. The survey will not include schools, workplaces, group quarters (dormitories, institutions, rooming houses, etc.), seasonal units, or unoccupied units. 

To permit inferences about the target population, probability sampling methods will be used in designing the survey. Sample collection and interview procedures being considered include face to face interviews using field study staff, random digit dialing telephone interviews or some combination of these procedures. The face to face procedure is the most likely method at the present time and will be described here to illustrate the manner in which the probability sample will be selected. 

Survey Design. The target population for the NHATS program Is... 

This volume includes evaluations of the carcinogenicity of several chemical intermediates or additives to which a large number of workers are exposed in various industries. Information on the extent of occupational exposures to many of these compounds in the United States was available from the National Occupational Exposure Survey (NOES) conducted by the United States National Institute for Occupational Safety and Health (NIOSH). NOES was a nationwide observational survey conducted in a sample of 4490 establishments from 1981 to 1983. The target population was defined as employees working in establishments or job sites in the United States of America employing eight or more workers in a defined list of Standard Industrial Classifications. 

An intense interest in insect pheromones has been generated around the world in the past few years as applications have been developed to use these biologically active compounds to detect, survey, monitor populations and, in some cases, to control the target insects. Pheromones have been identified for ca. 250 insect species ( 1) most of which are Lepidoptera. Many of these compounds or blends of compounds have been used as baits in survey or monitoring traps to detect or estimate insect populations some have also been successfully applied for mass trapping of males and as mating disruptants in insect control programs. 

This brief review has shown that there are some differences in the way dietary risk assessment is practiced between the US and the EU. Many of the differences have to do in the types of input data that are available, or in some of the methods used to collect the data. Regarding the food consun tion data, the US surveys use a dietary recall method, whereas the UK approach is a diary method that weighs and measures the amount of food consumed. In the US, data are collected for two non-consecutive days, whereas in the UK surveys, data are collected for either 4 or 7 consecutive days. The US survey is conducted as an integrated whole and includes all segments of the population. In contrast, the UK surveys are conducted for specific population groups. Finally, the US survey collects data at the household level, whereas the UK survey targets demographic characteristics, based upon census information. 

Unfortunately, consumer research is expensive. A good test requires a large population of respondents, and there is a limit to the number of samples each can test typically, a test which includes 20 products or perfumes may require interviews to be carried out with 1000 respondents, each testing four products (giving 200 assessments of each product). The survey respondents must represent the target population and, as far as possible, the survey must be carried out under realistic circumstances. For instance, a laundry powder perfume would be tested by a population who normally do the household shopping and washing. 

Probability surveys are surveys where samples are selected by a specified random process. The population from which the samples will be selected is called the universe or the target population. 

The data collected from these surveys are used to make inferences about the target population of wells which may be categorized in various ways. Some examples of target populations are wells in ... 

Before the specific survey types are discussed, some advantages of probability surveys should be mentioned. Such surveys are efficient in that results from a relatively small number of samples can be used to draw reliable conclusions about a large target population. The probability approach also reduces possible selection bias resulting from the let s grab a sample here because it looks good philosophy. Put in different words, the major obstacle to random selection is convenience - if it is more convenient to select sampling points in a particular fashion, the process is probably not random and should be avoided (12). 

Pilot studies were conducted at the four schools in area D during the school year 1983-4. These studies were used to test and develop the survey instruments and procedures and to collect preliminary data on solvent abuse in the area of investigation. As a result of these studies, it was decided to restrict the target population to third year (aged 13 to 14 years), fourth year (aged 14 to 15 years) and fifth year (aged 15 to 16 years) pupils. 

Another group not included in the survey are those pupils whose parents refused permission for them to take part. Eleven percent of the target population were excluded for this reason, although as noted earlier, there was some overlap... 

Surveying the literature on mega-transportation projects makes clear that research needs to be conducted in a timely manner. Too rarely have clear and accurate before pictures been attained so as to confirm predictive models and enhance the capacity of policy makers to adapt project-plans to best serve their target-populations. One commonly accepted belief is that the degree to which change occurs is in some sense proportional to the scale of the road/rail project. 

As discussed earlier in this text, person factors refer to subjective or internal aspects of people. They are reflected in commonly used terms like attitude, perception, feeling, intention, value, intelligence, cognitive style, and personality trait. You can find many surveys that measure specific person factors of target populations ranging from children to adults. Some of these factors are presumed to be traits, others are considered states. It is important to understand the difference when you consider the evaluation potential of a particular survey. 

The target number of commodity samples to be obtained in the OPMBS was 500, as determined using statistical techniques. A sample size of 500 provided at least 95% confidence that the 99th percentile of the population of residues was less than the maximum residue value observed in the survey. In other words, a sample size of 500 was necessary to estimate the upper limit of the 95% confidence interval around the 99th percentile of the population of residues. 

The demonstration of genotoxic activity in a pharmaceutical molecule may not necessarily translate into discontinuation of development and ultimate licensing of the product to be marketed. A survey of the Physicians Desk Reference reveals many examples of pharmaceutical products that have been shown to elicit genotoxic activity in one or more gene-tox assays.41 This observation indicates that other factors (such as risk, benefit, seriousness of ailment, target patient population, dosage, and frequency of administration, among others) are taken into consideration. 

Acidification is also a problem in surface wafer populations that were not surveyed in federal research projects. For example, although lakes smaller than 10 acres were not included in the NSWS. there are from one to four times as many of these small lakes as there are larger lakes. In the Adirondacks, tlie percentage of acidic lakes is significantly higher when it includes smaller lakes (26 percent) than when it includes only the target size lakes (14 percent). 

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