# variance's questions - English 1answer

2.384 variance questions.

### Negative value when Calculating variance in population mean [on hold]

I am following the Hunter-Schmidt method for a meta analysis of Pearson r values. I am wondering if there is a way in which to create 95 % credibility intervals when I have a negative value for ...

### 7 Why is binomial variance calculated as $p(1-p) / (n -1)$?

2 answers, 6.873 views variance binomial bessels-correction
I had to translate several given statistics equations into code, and I came across this formula: Variance of a simple random sample $= \frac{p(1-p)}{n-1}$ The sample in question are test letters ...

### 2 Looking for formalization of the idea of low-variance predictors

0 answers, 60 views variance games
In baseball, Bill James suggested using, to predict next season's winning percentageruns_scored^2/(runs_scored^2 + runs_allowed^2), rather than this season's ...

### 9 Statistical test to compare precision of two devices

I am comparing two temperature control devices both designed to maintain body temperature at exactly 37 degrees in anaesthetised patients. The devices were fitted to 500 patients forming two groups. ...

### 2 How to check if a process has constant variance?

I am using KPSS test to verify if my process has constant variance around the mean, but I am not sure if this is the correct test for my case. In KPSS the null hypothesis is that the process is ...

### What is the correct parameter range to choose when conducting a sensitivity analysis?

When conducting a (variance-based) sensitivity analysis, should I set the range of a specific parameter to its maximum allowable range, or restrict it to something more appropriate for my specific ...

### 2 Kriging variance results

1 answers, 142 views variance interpolation kriging heatmap
I'm quite a newb at statistics and interpolation, and I cannot understand how to interpret the error estimation computed by Kriging. For example, I performed kriging on temperature values (Celsius ...

### 1 Joint distribution of two related sample variances

Consider three time series x, v, w The distribution of the values that x,v,w take are zero-mean Gaussian, stationary and independent of time (no temporal colleration) and of each other. We know the ...

### Average sample size of two fishers z correlations

I am conducting a meta analysis of Pearson's r correlations. As there are two correlations , sometimes three , for the same study and dependent variable I have averaged the correlations via fishers z ...

### 1 Under which circumstances (hypothesis) is $X^T X = covariance matrix of (X)$ true? [closed]

0 answers, 34 views self-study variance covariance-matrix

### What is the variance of log response ratio when adding a constant to the means?

0 answers, 140 views variance meta-analysis ratio
Note: while I asked if is ok or not to add a constant to the log response ratio here, with this question I focus specifically on the formula of the variance of the log response ratio when adding a ...

### 3 AUC variance for estimators with randomness (e.g. Random Forest)

I know that we can calculate the standard error for the AUC for all estimators, assuming that the conditional density is fixed. What I'd like to do, however, is additionally account for the randomness ...

### 1 Average variability of small data set

0 answers, 13 views variance small-sample variability
I have data for 300 devices and each device has been tested a different number of times so some devices have 2 data points and some have 8. For example, one device scored 5, 6.5, 6.5, 6, 6, 6 whilst ...

### 2 Does applying standard normalisation lead to normal distribution?

Does applying standard normalisation to data variables mean changing the distribution of data variables to normal distribution having mean=0 and variance=1?

### 3 estimation of mean and variance [closed]

1 answers, 41 views variance estimation t-test
Why are so many efforts spent on estimation and comparison of mean, but not variance? For example, t-tests are used to comparing the population mean. When reporting the data, we usually describe ...

### 3 Variance of a linear combination of vectors

1 answers, 1.267 views probability variance matrix
Let $A$ and $B$ be two constant matrices and let $x$ and $y$ be two random vectors, what is the general formula for $Var(Ax+By)$? I know the formula for when $x$ and $y$ are scalar random variables ...

### 1 Quantify group homogeneity

0 answers, 3 views variance heteroscedasticity
I have a set of data which are responses to ten questions. I have done some text analysis which gave me 10 similarity matrices (one for each question) between all responses for each question. I ...

### Express analysis of deviance table as ANOVA

1 answers, 308 views anova variance
How can I express the following analysis of deviance in an ANOVA table , by hand not with R..

### 1 How to assess similarity of two sets of Principal Component Analysis loadings

A predictive model that I currently use relies on PCA with varimax rotation to reduce the dimensionality of the data (whether this is appropriate is a separate question). The dataset consists of ...

### What is “Entropic Capacity”?

I found this term on the Keras blog website, quoted below Your main focus for fighting overfitting should be the entropic capacity of your model --how much information your model is allowed to ...

### 3 Bias-variance decomposition with sklearn BaggingRegressor

There is an example given on the Scikit-Learn site that compares the bias-variance decomposition of the rmse of a single SVR model against a bagging ensemble. Unfortunately, the data is being ...

### 2 How to combine subsets consisting of mean, variance, confidence, and number of sampled points used?

1 answers, 2.164 views sampling variance mean error
I have a data set that has been divided into $n$ data subsets. I am sampling from each of these subsets and getting a tuple consisting of mean, variance, confidence and number of sampled points used. ...

### 1 How to convert estimated precision to variance?

I have a simple model in INLA (the regressor is a single model=iid term), which reports the precision of the hyperparameter. How ...

### What is high deviance/a poor fit for negative binomial regression?

0 answers, 16 views regression variance negative-binomial
I have data that I am attempting to model with negative binomial regression. However, I am aware that this data has a high degree of variation (I am looking at patent count data - a significant number ...