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Questions tagged [statistical-test]

A statistical test provides a mechanism for making quantitative decisions about a process or processes.

Statistical Tests

A statistical test provides a mechanism for making quantitative decisions about a process or processes. The intent is to determine whether there is enough evidence to reject a conjecture or hypothesis about the process. The conjecture is called the null hypothesis. Not rejecting may be a good result if we want to continue to act as if we believe the null hypothesis is true. Or it may be a disappointing result, possibly indicating we may not yet have enough data to prove something by rejecting the null hypothesis.

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Correlation coefficient between nominal and cardinal scale variables

I have to describe the correlation between a variable "Average passes completed per game" (cardinal scale) and a variable "Position" (nominal scale) and measure the strength of the correlation. For that I have to choose the correlation coefficient…
RubP
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Perform statistical analysis using binomial distribution

I am trying to use the binomial distribution to test whether a "random" model that just randomly responds "virginica" 50% of the time, "setosa" 25% of the time and "versicolor" the last 25% of the time to see whether my logistic regression model is…
Arron
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How to perform wilcox test on the result of train () function

I have the following code in R and I want to perform a statistical test (wilcox) to determine if there is a significance difference between the two models. set.seed(308) rand_search <- train( Effort ~ ., data = d, method = "svmRadial", …
Tanveer Jan
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How to apply wilcox test on the predicted data in R?

We use the following code for k-fold cross validation training data when we have one data file, set.seed(308) rand_search <- train( Effort ~ ., data = d, method = "svmRadial", ##Create 20 random parameter values tuneLength = 20, …
Khan
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How to separate bar plot?

I'm trying to plot a bar chart that represents a two way anova, but the bars are overlapping, does anyone know an easy way to plot a data set that way? data <- structure(list(nozzle = c("XR", "XR", "XR", "XR", "XR", "XR", "XR", "XR", …
Vitor Muller Anunciato
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normality test with pre-aggregated data

Using spark I aggregated data for each group (cohort) to only contain the mean, standard deviation, and variance. Now in a second step using python I would like to test for normality…
Georg Heiler
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How to create a vector when using For Loop?

I am trying to conduct a two sided sign test from 10,000 random normal samples of size 30. I am trying to extract the p-values given from the binom.test and put them into a vector but can't quite figure out how to execute this. set.seed(100) sample…
Andy Radisavljevic
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Mann-Whitney U test when only summary data (IQR, median) are available

When raw data is not available, which normally occurs when we obtain our data from different scientific papers, how is it possible to perform a Mann-Whitney analysis to test whether two samples are statistically different when only median, IQR and…
cloud91
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Python package for getting the maximum likelihood estimator for logistic regression

As this post is long, I will put my questions here: 1. Is there a package in python that will give me the maximum likelihood estimator parameters, for a given number of parameters p, for the covariates x and the data values y? (Preferably with…
Meep
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Bootstrapping residuals of a linear model

Suppose I want to assess the goodness of a linear model before and after leaving out a covariate, and I want to implement some kind of bootstrapping. I tried to bootstrap the sum of residuals of both models and then I applied the Kolmogorov-Smirnov…
Marco Repetto
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Does fitting a linear regression and performing t test will give similar results?

I am trying to predict the statistically significant variables out of a list of binary variables. I am having a conceptual doubt in the below mentioned 2 approaches to find the relevant variables. Dependent variable: Height of a person…
ShubhamA
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Chi-Squared test for independence with one data column as integer and other as object?

I'm trying to perform hypothesis test for Independence in python but my one data column(finances) has float data type and other column(gender) has object data type. I have created the following hypothesis: Ho : finances are gender independent Ha :…
Bhavishya
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How to read data into a contingency table in R

I am trying to implement the code from this link: http://rcompanion.org/handbook/H_09.html specifically the code for this example: "Example of extended Cochran–Armitage test 1" The problem is I am trying to read in a csv file containing the data for…
Ray92
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What kind of statistical analysis can I use to compare distance estimates in three experimental methods?

I have three data sets of distance estimates by humans in three different experimental methods such as (real life, virtual reality, and computer-based simulation). I want to compare how do humans differ in estimating distances in these three…
Rakshit Agarwal
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What do you do if the sample size for an A/B test is larger than the population?

I have a list of 7337 customers (selected because they only had one booking from March-August 2018). We are going to contact them and are trying to test the impact of these activities on their sales. The idea is that contacting them will cause them…
datababie
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