# All Questions

47 views

### Interpretation of this heatmap

Consider a synthetically generated dataset. Assume we have two groups of people, one is given diet pills, the other a placebo. Their weights are measured at 4 different days, namely, ...
70 views

### Does this look like a Cauchy distribution?

This is my data there is more actually... but I just want to know if this looks like a Cauchy distribution, such as these: I'm asking about just that bump... here is the whole distribution , ...
30 views

### Generating data from Probit regression, cut off 0 and variance 1 necessary?

I am trying to create a dataset using a Probit regression model in R, where I have an intercept and three covariates. I first fix a set of coefficients for the three covariates, generate these ...
5 views

### Repeated measures ANCOVA - heterogeneity of slopes

In my 2x2x2 mixed model ANCOVA, the covariate is interacting with only one of the main effects (repeated measures). Would it be OK to interpret the rest of the effects and interactions (which were not ...
6 views

### How many number of items should i include in my test?

I have designed two post test ,a recognition test and a production test.I have inserted 18 items in each test. As I sifted through articles , I 've read that we should include at least 30 items to get ...
29 views

### Does a lower t-stat suggest better evidence for rejection? [duplicate]

Say I have these two models: $y = \beta_0 +\beta_1x_1 + u$ $y = \beta_0 +\beta_1x_1 +\beta_2x_2 + u$ and the $p$ value for $H_0:\beta_1 = 0$ with $\alpha = 10\%$ for both is less than 0.001, but ...
45 views

### Why report r-squared in Instrumental Variables Estimation?

I mean the the R-squared calculated such as in $R^2=1-\frac{RSS}{TSS}$ when you use the $RSS$ from the original structural model and not recalculation that you should do in order to do an F test. With ...
6 views

14 views

### Data visualization tips for a 2x2 factorial design

The data stem from a 2x2-factorial design where both factors have two levels. The x-axis shows the words of a sentence and the y-axis the mean reaction time for each single word. Here is how I ...
33 views

### Optimal brain damage in R [on hold]

Is there any R package implementing optimal brain damage algorithm or anything similar what can be used to prune neural networks models?
23 views

### Can I apply factor analysis on multiple choice questions?

I am looking to validate a questionnaire and would like to know if I can use factor analysis on the multiple-choice questions (MCQ). Also, I have another section where I am asking about participants ...
18 views

### Treatment of mixed effect models for Box-Cox transformation

To analyse the Box-Cox transformation in a mixed effect model, no simple transformation/ code in R exists. So which of the following approaches would be valid ways and why? 1) Take a random sample ...
17 views

### Creating a copy/simulation of a dataset respecting statistical properties?

I often need to work with and analyse electronic medical record data which cannot be moved from the servers in the organisation where it resides, due to ethical reasons. Is anyone aware of a method or ...
26 views

### When to use Bayesian Networks over other machine learning approaches?

I expect there may be no definitive answer to this question. But I have used a number of machine learning algorithms in the past and am trying to learn about Bayesian Networks. I would like to ...
40 views

### Setting up a aov model in R for a variant of a 2-way nested ANOVA

I have a rather complex experiment i need to analyse The experiment was an infection trial, where the effect of two different infection methods ("inoculation" and "in-contact infection") were ...
39 views

### Should I use Mean Square Error or Classification Rate?

I am a self-taught person and I would like your help. I am learning about predictive modeling in general, and I'm also trying to do predictive modeling for a specific problem. I am exploring ...
17 views

### Can we boosting or stacking with different input variables for each model in machine learning?

I have a question about Boosting and stacking in machine learning. Suppose that I will train neural network, SVM and logistic regression using optimization algorithm to optimize best inputs in first ...
17 views

### Fisher's linear discriminant VS naive bayes

i know some basic things about linear classifiers. i prefer two think geometrically about them. and what'll happening if covariance Matrix were different things. Generally; What's the difference of ...
17 views

### Clustering MVT response data by audience

We are doing multivariate testing 4 possible values for each of 3 variables on a landing page: (a) offer presented, (b) product claim message displayed and (c) image used. So, 12 dummy variables, 64 ...
23 views

### Statistically prove that answers to questionnaire are not correlated to questions

I have a questionnaire of 4 "yes-no" questions: A1,A2,B1,B2. The correct answer for A1 and A2 is "yes", and the correct answer for B1 and B2 is "no". I need to statistically show the fact that ...
11 views

### Correlation between decision trees

How do you find the correlation between decision trees? I know this is an issue when working with random forests, but I can't find an explicit formula anywhere. I only get that random forest reduces ...
15 views

### Interpreting partial eta squared and reporting it apa style

How do you interpret and report partial eta-squared in a two-way anova? I have run a two-way anova to inspect whether gender and level of education interact to have an effect on positive affect. ...
13 views

### software or libraries to create document term matrix for arabic texts? [on hold]

Ideally I would like to analyze arabic texts without translating. Does anyone know any software or libraries for R or python that can make a document term matrix out of Arabic texts? Thanks.
20 views

### QQ plot in Python

I generated a qq plot using the following code. I know that qq plot is used to check whether the data is distributed normally or not. My question is what do the x and y axis labels indicate in qq plot ...