Examples of using Non-probability samples in English and their translations into Arabic
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Bit By Bit- Asking questions- 3.4.2 Non-probability samples: weighting.
With non-probability samples, weights can undo distortions caused by the assumedsampling process.
Now, I will show how that same idea can be applied to non-probability samples.
First, unadjusted non-probability samples can lead to bad estimates;
In the same way that researchers weight responses from probability samples, they can also weight responses from non-probability samples.
Bit By Bit- Asking questions- 3.4.3 Non-probability samples: sample matching.
First, unadjusted non-probability samples can lead to bad estimates; this is a lesson that many researchers have heard before.
Although“Dewey Defeats Truman” happened in 1948,it is still among the reason that some researchers are skeptical about estimates from non-probability samples. Source.
Unfortunately, when working with non-probability samples, we don't know how the sample was selected.
It is worth learning a bit more about their approach because it builds intuition about post-stratification, and the particular version Wang andcolleagues used is one of the most exciting approaches to weighting non-probability samples.
However, the second lesson is that non-probability samples, when weighted properly, can actually produce quite good estimates.
At this point, we lack solid theory andempirical experience to know when weighting adjustments to non-probability samples will produce sufficiently accurate estimates.
Probability samples and non-probability samples are not that different in practice; in both cases, it's all about the weights.
These techniques using auxiliary information are particularly important because, as I will show later, auxiliary information is critical formaking estimates from probability samples with nonresponse and from non-probability samples.
One thing that is clear, however,is if you are forced to work with non-probability samples, then there is strong reason to believe that adjusted estimates will be better than non-adjusted estimates.
The second lesson, however, is that non-probability samples, when analyzed properly, can actually produce good estimates; non-probability samples need not automatically lead to something like the Literary Digest fiasco.
For a meta-analysis on the effect of weighting to reduce bias in non-probability samples, see Table 2.4 in Tourangeau, Conrad, and Couper(2013), which leads the authors to conclude“adjustments seem to be useful but fallible corrections…”.
Sometimes, researchers have found that probability samples and non-probability samples yield estimates of similar quality(Ansolabehere and Schaffner 2014),but other comparisons have found that non-probability samples do worse(Malhotra and Krosnick 2007; Yeager et al. 2011).
Sometimes researchers have found that probability samples and non-probability samples yield estimates of similar quality(Ansolabehere and Schaffner 2014),but other comparisons have found that non-probability samples do worse(Malhotra and Krosnick 2007; Yeager et al. 2011).
Probability sampling versus non-probability sampling.
Online panels can use either probability sampling or non-probability sampling.
In evaluating the sentinel system,the national consultative committee raised concern about the non-probability sample selection methods and the rationale of inferring the sample results to the whole population.
Using this analysis strategy,Wang and colleagues were able to use the XBox non-probability sample to very closely estimate the overall support that Obama received in the 2012 election(Figure 3.5).
Non-probability sampling includes a huge variety of designs(Baker et al. 2013).
Because of the qualitative nature of the research, a non-probability sampling technique was devised.
In general, there is a cost-error trade-off with non-probability sampling being lower cost but higher error.
Figure 3.6: Probability sampling in practice and non-probability sampling are both large, heterogeneous categories.
The digital age is making probability sampling in practice harder andis creating new opportunities for non-probability sampling.
These newer methods are different enough from the methods that caused problems in the past that Ithink it makes sense to think of them as“non-probability sampling 2.0.” The second reason why researchers should reconsider non-probability sampling is because probability sampling in practice are become increasingly difficult.
However, well-done non-probability sampling can produce better estimates than poorly-done probability sampling. .