The stratification tag has no wiki summary.
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Can I perform a stratified test againts a true value?
I have a study where they randomized patients into 2 groups (A and B). The primary aim is to compare group A against a fixed/ true value of 0.75. The binomial test is not stratified and cochran mantel ...
7
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1answer
354 views
Empirical distribution alternative
BOUNTY:
The full bounty will be awarded to someone who provides a reference to any published paper which uses or mentions the estimator $\tilde{F}$ below.
Motivation:
This section is probably not ...
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0answers
29 views
For count data from a survey, do variance corrections for survey design imply that the Poisson distribution will not accurately model the counts?
I have categorical count data that comes from a complex survey. Each unit of analysis in the survey (household, individual, etc.) is put into one and only category per dimension, ranging from 2 to 20 ...
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1answer
67 views
Analysis of complex sample
The company where I work did a survey with a complex sample. Originally, the sample was a 2-step stratified, but due to some problems, we lost one of them (so, let's consider that the sample is ...
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1answer
58 views
clustered-stratified random sampling
i've got questions about clustered-stratified random sampling.
let's say I want to do a research in narcotics.
the population that I will be working with is a combination of academics, students, and ...
2
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1answer
214 views
When do you stratify an analysis versus including an interaction term?
I’m not very familiar with when and why you would stratify on a variable or set of variables in a regression analysis generally and would like to know what the issues are particularly in contrast to ...
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35 views
Understanding stratified CV
What is the difference between stratified CV and CV?
Wikipedia says:
In stratified k-fold cross-validation, the folds are selected so that
the mean response value is approximately equal in all ...
4
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1answer
188 views
Fisher overall p-value vs. pairwise comparisons
I am doing comparisons on response rates across three sites. Following are the cell counts
...
3
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2answers
148 views
Beta coefficients from stratified analysis when there are covariates?
Suppose I have a regression model shown below
Model 1:
$$
Y = \beta_0^\ + \beta_1SEX\ + \beta_2ALCOHOL\ + \beta_3SEX*ALCOHOL\
$$
The predictors I am interested in are SEX (binary: 0 female, 1 male) ...
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59 views
different results between models with interaction and when stratifying
I have a question about the reason of getting different results between a model where i introduced a cross term for interaction between a continuous and categorical variable (3 classes), and when i ...
4
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1answer
50 views
What are the optimizations or goals to consider when using stratified sampling?
In stratified sampling, what are the optimization considerations? For example, the sample size per stratum could be defined with proportional allocation as $n_h=n\frac{N_h}{N}$, where $N_h$ is the ...
1
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1answer
139 views
Possible catch 22 with Neyman's optimal allocation
I am using stratified sampling and neyman's optimal allocation to compute the best sample size for each stratum. neyman's optimal allocation is given by the formula,
$$n_h = n \frac{N_h * S_h}{\sum_i ...
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2answers
322 views
Why is random assignment important in stratified sampling?
Background
I raised this question because of an argument I am having with a question from user697473 here. The title of his question is "Formal definiton of random assignment." In the post he ...
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1answer
200 views
Stratified classification with random forests (or another classifier)
So, I've got a matrix of about 60 x 1000. I'm looking at it as 60 objects with 1000 features; the 60 objects are grouped into 3 classes (a,b,c). 20 objects in each class, and we know the true ...
0
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2answers
54 views
What is the name of this type of stratifed sampling?
I am not sure what this specific type is called so I will describe what I did in Excel. This was employee data:
Sample size is prescribed. Example: n = 100 (though the population N = 10000)
Sort ...
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0answers
49 views
Choice of calibration totals
If I have fully cross-classified population totals on several attributes, how do I choose which interactions to skip when defining the calibration totals?
In a survey reweighting exercise, I have ...
4
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1answer
123 views
How to efficiently expand a simple random sample after population growth?
I have a simple random sample (SRS) $S$ of size $n$ drawn from a population $D_1$ containing $N_1$ members. A new set $D_2$ with $N_2$ members is added to the population. I would like to create a ...
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3answers
135 views
Derive househould weights from a uniformly distributed person sample
The Swiss Public-Use Sample of the national census is a 5% sample drawn from the entire census survey. According to the documentation, the persons are sampled uniformly without replacement. Persons ...
1
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1answer
101 views
Remove duplicates from training set for classification
Let us say I have a bunch of rows for a classification problem:
$$X_1, ... X_N, Y$$
Where $X_1, ..., X_N$ are the features/predictors and $Y$ is the class the row’s feature combination belongs to.
...
2
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1answer
485 views
Stratified sampling with multiple variables?
I don't know much about stats so I'm looking for a starting point here. Any resources or insights would be helpful.
I'm conducting an e-learning experiment, in which students watch videos and then ...
2
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1answer
321 views
Stratified Cox model
I am working on fitting a Cox model to predict. But several predictors violated the proportional hazards assumption. I am gonna to do stratified Cox model to adjust them. But the results of stratified ...
2
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1answer
607 views
Bootstrapping stratified sample that is weighted to population - reweighting during the bootstrap?
I'm using R to provide bootstrap (percentile and t methods) of estimated population totals, using data from a complex survey. It is a stratified survey of tourists expenditure that is weighted to ...
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2answers
219 views
When using stratified randomization in a RCT, how many envelopes per stratum should be prepared?
If one considers a hypothetical RCT, say a total sample size of 300, separated into three strata based on surgical procedure (open surgery, closed surgery, or combined procedure). Blocking in groups ...
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2answers
217 views
Stratified sampling question
Good day all,
Suppose that I am conducting a questionnaire study that is trying to measure level of awareness of subjects about a programming language and find the relation of those level of ...
5
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2answers
644 views
Simple post-stratification weights in R
I just got my hands on the ANES (American National Election Studies) 2008 data set, and would like to do some simple analysis in R. However, I've never worked with this complex of a data set before ...
