Questions tagged [pooling]
Pooling, eg for variance, is used when several groups or populations are assumed to have a common property (a common parameter value) and the information from all the groups or populations are used together to estimate that common property.
293 questions
4
votes
1
answer
118
views
Negative F-value from micombine.F in miceadds after pooling positive F-values
I'm using the mice and miceadds packages in R to perform multiple imputation and then analyze the results.
Here's what I did:
I performed multiple imputation on my dataset using the mice package.
For ...
0
votes
0
answers
44
views
How does PCSE work? (panel corrected standard errors)
I have read that PCSE (panel corrected standard error) can model autocorrelation by adjusting standard error to account for it. would this be an ideal solution ?
2
votes
0
answers
82
views
Average the statistic values or average their corresponding p-values?
Say I am computing Hopkins statistic of clustering tendency. The statistic compares the data cloud with the cloud of points randomly and uniformly simulated in the same spatial region. Under the null ...
0
votes
0
answers
78
views
Calculating Partial Eta Squared for Pooled Results After Multiple Imputation in R
I’ve been struggling with this question for a while, so any help is much appreciated!
I’m trying to calculate an effect size (partial eta squared or $\eta^{2}_p$) for an ANCOVA model using pooled data ...
0
votes
0
answers
52
views
Pooled variance VS BLUE estimator
I was wondering, suppose I receive a list of results (e.g., two independent variables A and B that estimate the same value), I could perform a hypothesis test to check whether the two variances are ...
0
votes
0
answers
48
views
Between estimator versus pooled OLS/Random effects
I am familiar that, for example, Hausman's test can help me pick which is better between a fixed-effects and a random-effects model. But is there a test that can help me choose between a between ...
0
votes
0
answers
127
views
Estimation of pooled prevalence (with 95%CI) in imputed and weighted data in R
I am trying to estimate the prevalence of a binary variable "x" and its confidence interval after multiple imputations (using mice) and applying weights in R. I use Rubin's rules for the ...
0
votes
1
answer
80
views
How to obtain one study effect from several within-study effects?
I want to do a narrative review (as a meta-analysis is not possible), and I want to conclude per study whether the predictor was significant yes/no. However, studies have several effect sizes per ...
1
vote
1
answer
48
views
Include two groups post-test design study for meta-analysis pool?
I am new to meta-analysis and currently trying to find effect of intervention on service users.
Most of the studies that I found were RCTs or quasi-experimental studies with 2 groups pre-post test ...
1
vote
0
answers
88
views
Why is a pooled mean necessary in bootstrapping the difference in means?
Formulated Question
In a two-sample bootstrap procedure for testing the difference in means, why is it insufficient to subtract the group-specific mean from each bootstrapped observation (centering ...
0
votes
1
answer
136
views
How to compute a pooled standard error [duplicate]
I am comparing $m$ methods across $d$ datasets. Through my experiments I have obtained the mean, the standard deviation, and the standard error for all methods and all datasets, hence I have the means
...
0
votes
0
answers
110
views
Pooling Model Results with Rubin's Rule for Multiple Responses (Same Predictors, Different Outcomes)
I understand that Rubin's rule is commonly applied for pooling model results across multiple imputed datasets, where the same set of predictors and response are used, like this:
...
3
votes
1
answer
153
views
Determining biological replicates with pooled samples
Our group has had a long-standing protocol wherein multiple tissue purifications are pooled. This is because there is very little of the tissue per animal. This pool was then sampled several times and ...
1
vote
1
answer
239
views
How to pool results of type II ANCOVA from multiply imputed data set?
I'm using MICE to impute a small data set. I am going to use ANCOVA of type II through Anova function of R package car. However, ...
3
votes
1
answer
238
views
How to conduct statistical analysis on multiply imputed data?
I have a data.frame named mydata with 6 columns: status, times, t1, t2, t3, t4. However, t1, t2, t3, and t4 contain missing values in this dataset. I intend to impute these missing values using the ...
3
votes
1
answer
220
views
Bootstrap standard errors after multiple imputation
Following Rubin's rules for multiple imputation, I've calculated pooled estimates, group means in this case, with pooled standard errors.
I checked this with a bootstrap and, assuming pooled standard ...
0
votes
0
answers
68
views
Estimating variance from several samples
If several samples are taken from a distribution, say Gaussian, each sample having size n1,n2,n3,... and the SD of the underlying distribution is estimated from each of the samples, how can those ...
0
votes
0
answers
71
views
Standard error of mean with varying replicates for batches
I have three batches of simulations and I calculate a specific property from these (not important for the question). I want to calculate combined SEM for these three batches
Batch | #samples | ...
1
vote
0
answers
37
views
How can I combine/pool the results of regression ANN? [closed]
In my analysis, the data contains 5 imputed dependent variables. So, after analyzing all of the dependent variables separately with a regression neural network, I need to combine/pool the results. ...
3
votes
1
answer
204
views
In multilevel logistic regression, can pooled data return significant variables when the same variables in stratified data are not significant?
I have analyzed some secondary data that relates to Plasmodium infection at three forest sites: inside the forest, at the forest fringe, and outside the forest.
The outcome variable is infection with ...
1
vote
0
answers
74
views
Combining data before and after protocol modification
In one of my research, we decided to "update" the procedure mid-study.
In short, we initially tested a repeated measures design (1 factor with 3 levels, 5 times per condition for a total of ...
0
votes
0
answers
53
views
Panel vs Pooled OLS
My sample comprises of data on accounting performance of companies that had their IPOs between 2009-22. I want to examine if companies which had more foreign investor participation in their IPOs ...
4
votes
1
answer
304
views
Why does Partial Pooling occur in Mixed Effects Regressions?
I am trying to create an intuitive example which shows why Mixed Effects Regression models perform Partial Pooling in the background. I previously tried to demonstrate that Mixed Effects Regressions ...
1
vote
1
answer
410
views
Panel Data Estimation and Control Variables
My undergrad thesis has something to do with the relationship between emissions, mitigation-related official development assistance, and governance variables in chosen ASEAN countries. As such, my (...
3
votes
0
answers
171
views
Pooled Kurtosis Estimator Using Pooled Cumulant Estimators
I am trying to come up with a statistically sensible pooled kurtosis estimator that is based on pooled cumulant estimators.
Specifically, I have unbiased estimators of the second and fourth cumulant ...
1
vote
0
answers
168
views
Bayesian hierarchical exchangeability assumptions reasonable with a check treatment?
This is information I believe to be true
A practical feature of hierarchical Bayesian models is that partial pooling reduces (eliminates?) the need of adjusting for multiple comparisons when ...
6
votes
1
answer
681
views
Pooled Standard deviation of means
I am reading the book Statistical Methods In Online A/B Testing.
I have two questions:
1.
Please Consider the scenario, an A/B test in which the variance of A and B groups are assumed to be same, and ...
2
votes
1
answer
73
views
Pooled analysis of different but very similar measures; what is the best practice?
I have three small data sets which include scores on global cognitive assessments. Two data sets use the score on the Mini Mental State Exam, one uses the score of the Montreal Cognitive Assessment. ...
0
votes
0
answers
76
views
How to impute the std deviation of a sample using the pooled mean and standard deviation of similar samples?
I want to perform a meta-regression based on the mean changes from baseline values.In one of the studies, the standard deviation has not been mentioned. How can I impute the value of the missed ...
1
vote
2
answers
264
views
Consistency of the pooled standard deviation estimate
Suppose that $X_{ik}\sim\mathcal N(0,\sigma^2)$ for $k = 1,2,\dots, n_i$ are independent and identically distributed for each $i \in\{ 1,2\}$. Note that I assume equal means ($0$) and variances ($\...
1
vote
0
answers
109
views
How does a fixed-effects regression improve on a pooled OLS regression with non-normal residuals, heteroskedasticity and autocorrelation?
I am running a pooled OLS regression as a benchmark model on a panel data set of online forum member activity. The aim of the model is to understand the relationship between exposure to hate speech ...
0
votes
0
answers
64
views
Is it possible to "unpool" a pooled variance if the population variances are not equal?
I recognize that if the population variances are not equal, it's not really a pooled variance to start with, but I wanted to keep the question succinct. The scenario here is that I begin with a sample ...
1
vote
0
answers
51
views
How rigorously can boundary conditions on statistical power of stratified analysis vs. pooled analysis be defined?
I spend a lot of time thinking about conditions under which various kinds of analyses perform well. To some degree I am hoping NOT to specify too many specifics here (because part of what I am ...
0
votes
0
answers
103
views
When to pool batches for tolerance intervals?
Imagine that we have at disposal several batches of data from a given process and that the interval time of record of each batches can be week, months or even years.
Out of these data, we would like ...
0
votes
0
answers
38
views
Sign change of main variable when I add the interaction tetm [duplicate]
I am running pooled regression for 67 group my dependent variable is gini disposable and independent variable is women empowerment (economic,social,political) and institutional quality ( government ...
1
vote
0
answers
129
views
Attributing variance to fixed and random effects / partial pooling in glmmTMB
I have a dataset with counts of birds in two locations over time, and am interested in describing the difference in trends in bird counts between these locations. The counts are conducted by multiple ...
0
votes
0
answers
57
views
Link test for pooled logistic regression
After logistic regression of the cross-sectional data sets, link test _hatsq shows insignificant. However, when I pool the same two data sets, the link test using the same set of variables regression ...
3
votes
0
answers
92
views
How to pool estimates from multiply-imputed datasets with complex sampling designs?
Analysts often use Rubin's rule (RR) to obtain a pooled estimate of a popular quantity from multiple (imputed) datasets. While popular statistical software (such as the R ...
1
vote
1
answer
1k
views
Multiple imputation MICE categorical variable: problem with pooling after running ANOVA
I am trying to answer a question about satisfaction and its relation with a certain variable (numeric, 1-10). However, my data contains a lot of missing values in the satisfaction outcome, therefore I ...
0
votes
2
answers
2k
views
Cox Regression on multiple imputed datasets (R)
I fit a cox regression using the coxph function of the survival package. Now I wanted to do the same on a multiple imputed data set (which I already have, generated in another software). I found some ...
2
votes
0
answers
82
views
Approaches to (non-linear) meta-regression to estimate the conditional population distribution of $y$ based on aggregate data
I want to estimate the distribution of a variable in certain subgroups of the population based on pooling of aggregate data reported in various observational studies. For simplicity, assume there is a ...
4
votes
2
answers
2k
views
How can I average the variance extracted from different group of samples?
I have groups of samples, where each group has a different number of samples and a different mean. I also know the variance of each group of samples. I would like to compute a sort of "average&...
0
votes
0
answers
183
views
Is there a way to fit a machine learning model to MICE imputed datasets and pool the results?
I have a medical dataset that has a lot of missing values. I imputed five datasets using MICE in R. I want to fit a classification machine learning model to the dataset. I want to identify the most ...
0
votes
0
answers
551
views
Multiple logistic regression odds ratio on multiply imputed data in R
I am running a hierarchical logistic regression analysis using multiply imputed data in R (using the mice and miceafter packages). I am unable to get the odds ratio and 95% CI per variable adjusted ...
2
votes
0
answers
174
views
Pooled standard deviation of two correlated variables [closed]
I'm trying to calculate an effect size index where I need to pool 2 standard deviations calculated from correlated variables (pre-post treatment scores). Using the standard formula:
$$
\sigma^2_{...
5
votes
1
answer
2k
views
What is the difference between "repeated cross-section" and "pooled cross-section"?
What is the difference between "repeated cross-section" and "pooled cross-section"?
Pooled cross-section is defined e.g. here as "randomly sampled cross sections of ...
1
vote
0
answers
451
views
Is downsampling necessary in CNN?
I am still trying to understand the effect of any downsampling (reducing the input height and weight by 2 for example) by pooling or strided convolution? Does downsampling improve accuracy?
Because in ...
1
vote
0
answers
218
views
Pooling SHAP values from multiple imputed data
I have multiple imputed data and will be conducting an identical lightGBM model with the same input features in each of the imputed datasets. My aim is to calculate SHAP values (SHapley Additive ...
0
votes
0
answers
119
views
How to choose the best converging imputations for my CFA model and pool them
I have 70 imputations of my original data set. I want to choose 50 of them which converged after less than 120 iterations on my CFA model:
...
2
votes
0
answers
401
views
Why not using Convolutional pooling instead of MaxPooling to avoid invariance
I was reading the paper of [Geoffrey Hinton: Capsule network], and I watch it's talk on Youtube about the problem of Conv Network is actually the (max) pooling layer, since we don't want to be ...