Linked Questions

3
votes
2answers
3k views

Should I report the descriptive statistics in publication before or after outliers removal?

I have already removed three outliers from the ANOVA and ANCOVA analysis to improve the models. I want to report the descriptive statistics and p-values. First I removed these outliers, and then I ...
11
votes
2answers
5k views

machine learning techniques for longitudinal data

I was wondering if there were any machine learning techniques (unsupervised) for modelling longitudinal data? I've always used mixed effects models (mostly non-linear) but I was wondering if there are ...
1
vote
1answer
63 views

source info for a cartoon [closed]

I want to use this image in a presentation for teachers and I cant find the source, when I drop it in google images your site comes up, any idea of the source?
4
votes
2answers
216 views

Compute a Pvalue from the averaged Pearson and Spearman rho

On the one hand, Pearson correlation is sensitive to outliers, while Spearman is not. On the other hand, if you have quantitative data, Spearman will treat it like ordinal data. How about averaging ...
3
votes
1answer
191 views

What is not normal distribution?

I am running analyses for my dissertation and just got myself in a muddle. I am running descriptive stats to determine whether to use paired t-tests vs Wilcoxon signed rank tests. I've read that it ...
44
votes
6answers
4k views

What is your favorite statistical graph?

This is a favorite of mine This example is in a humorous vein (credit goes to a former professor of mine, Steven Gortmaker), but I am also interested in graphs that you feel beautifully capture and ...
2
votes
1answer
299 views

Creating a composite rank of restaurants with some missing data

I have monthly sales data of 500 restaurants for one year. For the same restaurants, I also have customer defection or dissatisfaction rates. I want to create a composite score that can rank ...
2
votes
1answer
3k views

Average of root mean square error

Is taking the average of different rmse valid? for example average rmse = (rmse1+rmse2+rmse3)/3 Thank you for your help!
60
votes
3answers
21k views

Explain the xkcd jelly bean comic: What makes it funny?

I see that one time out of the twenty total tests they run, $p < 0.05$, so they wrongly assume that during one of the twenty tests, the result is significant ($0.05 = 1/20$). xkcd jelly bean ...
16
votes
4answers
5k views

Which to believe: Kolmogorov-Smirnov test or Q-Q plot?

I'm trying to determine if my dataset of continuous data follows a gamma distribution with parameters shape $=$ 1.7 and rate $=$ 0.000063. The problem is when I use R to create a Q-Q plot of my ...
20
votes
3answers
31k views

Is a p-value of 0.04993 enough to reject null hypothesis?

In a Wilcoxon signed-ranks statistical significance test, we came across some data that produces a $p$-value of $0.04993$. With a threshold of $p < 0.05$, is this result enough to reject the null ...
1
vote
1answer
1k views

Problems with modeling a cumulative dependant variable

I am building a .NET program. One of its functions is to provide a predictive model for a vehicles life-to-date maintenance costs, basically what is the cumulative cost(Y) for a vehicle at specific ...
46
votes
8answers
5k views

Pitfalls in time series analysis

I am just starting out self-learning in time series analysis. I have noticed that there are a number of potential pitfalls that are not applicable to general statistics. So, building on What are ...
14
votes
4answers
3k views

What is randomness?

In probability and statistics, the concept of "random" and "randomness" are frequently used. Often the concept of a random variable is used to model events that occur due to chance. My question ...
35
votes
3answers
37k views

Significance contradiction in linear regression: significant t-test for a coefficient vs non-significant overall F-statistic

I'm fitting a multiple linear regression model between 4 categorical variables (with 4 levels each) and a numerical output. My dataset has 43 observations. Regression gives me the following $p$-...

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