External validity & non-probability sampling
نویسندگان
چکیده
منابع مشابه
External Sampling
We initiate the study of sublinear-time algorithms in the external memory model [14]. In this model, the data is stored in blocks of a certain size B, and the algorithm is charged a unit cost for each block access. This model is well-studied, since it reflects the computational issues occurring when the (massive) input is stored on a disk. Since each block access operates on B data elements in ...
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External validity is a challenge in treatment effect estimation. Even in randomized trials, the experimental sample often differs from the population of interest. If participation decisions are explained by observed variables such differences can be overcome by reweighting. However, participation may depend on unobserved variables. Even in such cases, under a common support assumption there exi...
متن کاملTheory and External Validity
Winer (1999 [this issue]) proposes that external validity concerns require more attention in theoretical research. The author argues that one cannot “enhance” external validity by choosing one method over another. External validity can only be “assessed” by better understanding how the focal variables in one’s theory interact with moderator variables that are seen as irrelevant early in a resea...
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This paper presents a brief synopsis of the historical development of hybrid sampling designs that combine traditional probability based sampling techniques with non-probability based quota designs to create model-aided sampling (MAS) designs. The MAS approach is illustrated for an application to a national business establishment survey called the Occupational Information Network (O*NET) Data C...
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When an experiment is conducted, such as tossing coins, rolling a die, sampling for estimating the proportion of defective units, several outcomes or events occur with certain probabilities. These events or outcomes may be regarded as a variable which takes different values and each value is associated with a probability. The values of this variable depends on chance or probability. Such a vari...
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ژورنال
عنوان ژورنال: Indian Journal of Medical Research
سال: 2015
ISSN: 0971-5916
DOI: 10.4103/0971-5916.159311