# All Questions

211,779 questions
Filter by
Sorted by
Tagged with
2 views

### Multiple IVs and DVs with non-normally distributed data

I am performing a research study aiming at answering the research question: How does job design satisfaction differ between employees working in hybrid and remote work arrangements? For that I ...
10 views

5 views

### Is there a known way of producing forecasts with reasonable fit and residuals that are at least independent, & ideally negatively correlated?

I am trying to do some forecasts. I have produced multiple forecasts by a variety of methods. All of the forecasts I have generated so far have residuals that are strongly positively correlated.I ...
• 3,047
4 views

### My results for chi square analysis is not tally with the visualized gbarstats

I am working on chi-square test to test for an associations between variables. I used data_chi_GROUP = table(data$SEROPREVALENCE, data$GROUP) ...
20 views

### Purpose of expressing data in principal components

I have a rough understanding of the outline PCA. Given $n$ samples of $m$-dimensional data: $\vec{x}_1, \vec{x}_2, \dots, \vec{x}_n$, PCA aims to find an appropriate orthonormal basis called principal ...
• 101
7 views

### Infrastructure Score for Data Envelopment Analysis

I am planning to use survey questionnaire to determine infrastructure score with relevance to its quality and quantity. Can I use this for a DEA study? and to what extent?
3 views

### Including Covariate P-Values in Multiple Comparison Corrections"

I'm currently working on a statistical analysis involving multiple comparisons and I'm uncertain about a specific aspect of the process. Specifically, my question is about the inclusion of p-values ...
• 33
14 views

### How do we prove that the rows or columns of a hat matrix sum up to 1, when mean function includes an intercept?

Every textbook I encounter tells me that this is simply a meaningful relationship of a hat matrix, without explaining why: If H is the hat (projection) matrix, and our X matrix has full rank and a ...
7 views

### Converting a stata program to SAS

What is the equivalent of the following stata program to SAS? regress weight height if age==1 est store age1 regress weight height if age==2 est store age2 regress weight height if age==3 est store ...
6 views

### Diffrence in logs vs. a % changes in econometrics: why is the dif log approvimation almost always used when the exact quantity is easily available?

I have observed that in econometrics work people almost always use the difference in logs rather than the actual percentage change. This makes no sense to me. I understand that the difference in logs ...
• 3,047
32 views

### Computing Z scores AP Psych

My report is looking at the effect of belief in conspiracy theories and critical thinking abilities, on engagement in politics. I've basically got to do a factorial ANOVA and my IV's are: Conspiracy ...
1 vote
11 views

### Impute missing value [closed]

In machine learning when I impute missing values which of the following I perform : 1-Impute data set and then split it? 2-Split dataset to Training and testing datasets and then Impute each datasets ...
• 335
1 vote
18 views

### Motivatation behind moving average models [duplicate]

Suppose I have a time series with mean $0$. If I was assuming an $MA(1)$ model, then my prediction at each time $t$ would be proportional to how "off" my last prediction was. This feels ...
5 views

### Time order problem of control variables in IV regression

Y is the dependent variable, X is the independent variable, and C is a control variable. However, since X is endogenous, I plan to use an instrumental variable Z for X. From what I understand, if I ...
5 views

### Beyond AR(1) as a covariance structure for mixed models with repeated measures

I have been reading about alternatives to assuming an AR(1) covariance structure for mixed models with repeated measures (in time). In particular I have heard about Toeplitz and Ante-dependence ...
• 53
10 views

### Why is validation accuracy fluctuating between two extremes?

I am using a LSTM to make a multi-label classifier. However the problem is, the validation accuracy fluctuates between 0.7 and 0.3. I have about 4367 samples (80-20 validation split) and 240 sample ...
• 1
7 views

### Rationale for box-constrained optimization in adversarial example search

In Section 4.1 of "Intriguing properties of neural networks" by Szegedy et al., the authors define the optimization problem they solve to find adversarial examples in a deep neural network. ...
• 249
22 views

### Does applying a variable transformation to experiment data result in p-hacking?

From formal statistics classwork and some research experience, I understand that it is widely considered standard practice to apply transformations to predictor variables for conducting significance ...
• 21
1 vote
13 views

### Best Textbook for a Rigorous Treatment of Panel Data

I was wondering which book you recommend for a treatment of panel data that is both rigorous and intuitive. What do you recommend among Wooldridge(2010), Baltagi(2021), and Hsiao(2022)? I studied ...
• 239
1 vote
27 views

### Expectation of the Gaussian likelihood

I'm working on a challenging machine learning problem, where I need to find the expectation of the likelihood of one Gaussian, given the parameters of another. Apologies if any of the notation is ...
21 views

### Calculate multivariate betas using correlations and standard deviations [duplicate]

In a simple regression context: $$y = \alpha + \beta x + e$$ We can estimate beta from: $$\hat{\beta} = \frac{cov(x,y)}{var(x)} = \rho_{xy} \frac{\sigma_y}{\sigma_x}$$ This last decomposition is ...
27 views

### How to classify lists of 2 values (a,b) according to how close values of b are to another value of b?

I'm hope this is the correct forum for this but the gist of the problem is this: If I have a list of 12 values like this: 0,0,0,1,0,0,0,1,0,0,0,1 - then my frequency rate of 1 is 3/12 = 25% The same ...
• 1
1 vote
65 views

### What is the posterior probability for flipping a coin, assuming a beta distribution as conjugate prior

Suppose, I toss a fair coin n = 10 times and get 7 heads and 3 tails. The probability of fair coin is p = 0.5. Now, that the beta distribution is a conjugate prior of the binomial likelihood. I used ...
14 views

### Question about Gaussian Mixture model [duplicate]

suppose I have two parameters: $(\mu_{1},\Sigma_{1},\alpha_{1},\mu_{2},\Sigma_{2})$ and $(\mu_{1},\Sigma_{1},\alpha_{1},\mu_{2},\Sigma_{2})$ and suppose I mapped them to PDF using the gaussian mixture ...
• 133
9 views

### The least-squares dummy variables estimator vs fixed effects estimator in panel data

Is the least-squares dummy variables estimator never more efficient than the fixed effects estimator? I mean both should be consistent under the same assumptions. Quite often we assume in panel data a ...
29 views

• 349
1 vote
9 views

### High Standard deviation for regression coefficient in multilevel model with random slopes compared to fixed slopes

Recently, I compared two multilevel models of the same data: One with fixed slopes: R Code: lmer(RT ~ Kontrast + (1|ID) + (1|Satz), data = reading_times, REML = F) and one with random slopes: lmer(RT ~...
• 41
14 views

### For relationship between cycling and weather variables: multivariate linear regression? PCA?

Ive been having some trouble determining which analysis to run for a project of mine looking at the relationship between cycling and env variables. I would like to include two different types of ...
14 views

### Making a multiclass classification problem binary during data preprocessing vs using a multiclass classifier

Sometimes you have a problem that presents as a multiclass problem in your data, but you only care about the result of a binary classification. E.g. you have a manufacturing process which can result ...
1 vote
144 views

### Are there cases where we need to avoid the usage of IQR?

Let's consider the interquartile range (IQR), the standard deviation (SD) and the mean absolute deviation (MAD). We know that "one of the most common robust measures of scale is the interquartile ...
• 198
15 views

### Retrieving the variance partition coefficient of the frailty() term (mixed effects) for cox regression in R

I am new to running survival analyses. I am attempting to construct a cox regression using the coxph() function. I want to include a ...
1 vote
25 views

### Should I delete samples from the training data that are present in the testing data by accident?

I classify pairs of entities, let's say dog-cat pairs, whether there is association between them (positive class) or there is not (negative class). I have a moderately sized positive dataset (~130k ...
• 85
15 views

### Test for whether method decreases the metric or not

we have created a software for a given task. What we wanted to achieve is 1) to speed up the process 2) without lowering the quality of the work. Now I would like to run a test to see if 2) stands. My ...
20 views

### Paired Comparison on $n$ Tests, Repeated $k$ Times Each

Suppose I test two subjects on $n$ pass/fail (Bernoulli) tasks, $k$ times each—for a total of $n\cdot k$ tests per subject. I want to compare the subjects to see if there is a statistically ...
31 views

• 811