All Questions
Tagged with computational-statistics statistical-significance
31 questions
4
votes
1
answer
107
views
Check if a coin flips randomly, but it can have a different number of sides each toss
I would like to check if a coin flips randomly, based on observational data. The catch is, the coin can have two sides, but also three, four, up to nine. The number of sides differs in each ...
1
vote
0
answers
440
views
Compute a Monte Carlo estimate. Which of the variances (of $\hat{\theta}$ and $\hat{\theta}^{*}$) is smaller, and why?
Compute a Monte Carlo estimate $\hat{\theta}$ of $$ \theta = \int_{0}^{0.5} e^{-x} dx $$ by sampling from Uniform$(0, 0.5)$, and estimate the variance of $\hat{\theta}$. Find another Monte Carlo ...
1
vote
0
answers
33
views
Generate data for significance testing
I want to generate a data set with a pre-specified significance level.
Let's say we have 2 covariates x1, x2, and an outcome variable y.
We fit a linear regression model as follow:
...
1
vote
1
answer
466
views
How to interpret p-values in terms of correlation?
I have one datamatrix and a single column(let's say it fvector). I had find the spearman's correlation of each column from datamatrix with fvector i had setted the parameters as p <0.05 and i got ...
2
votes
1
answer
730
views
Which statistical tests can I use to analyse significant difference between the means of non-random samples? [duplicate]
I want to compare the means of non-random samples to population mean. However, most standard tests (eg. t-tests, ANOVA, Welch test etc.) are based on the assumption that samples are randomly obtained ...
2
votes
1
answer
247
views
Variable is not statistically significant in single variable linear regression but is significant in multiple regression
I had a friend ask me about this question, and I'm not 100% sure about the data she's using due to the sensitivity/privacy of the data (other than it's medical data). Sorry for not providing context, ...
0
votes
1
answer
98
views
How to test the difference of two linear regression slopes with 2 independent and one dependent variable
I am trying to determine if the CO2 emissions growth rate of developing countries is higher than the growth rate of developed countries. So essentially I need to compare two linear regression slopes ...
2
votes
3
answers
49
views
Suitable multiple testing procedure for three very correlated phenotypes
I have ran an analysis using polygenic risk scores including genetic variants at different p-value thresholds and have the following outcomes: IQ ages 8 and 9, strengths and difficulties questionnaire ...
5
votes
1
answer
7k
views
When to switch off the continuity correction in chisq.test function?
From this Research paper Table1 Association of RAD51-AS1 expression with clinicopathological features of EOC patients I see that p-value is calculated based on Chi-...
2
votes
2
answers
4k
views
Create an A/B Sample Size Calculator using Evan Miller's Post
To learn more about A/B Testing sample sizes selection I am attempting to use Evan Miller's popular blog-post to recreate a sample size calculator (https://www.evanmiller.org/sequential-ab-testing....
0
votes
1
answer
264
views
What is the analytical test to run in case of 1 measure for three groups?
I have this case where the data look like that
Trial Person 1 person 2
1 4.7. 3.8
2 7.1. 6.3
3 5.4. 4.5
I want ...
2
votes
0
answers
529
views
Are there any quantitative metrics for how representative a sample is?
I'm interested in selecting a sample that is representative of a population. Additionally, I want to be able to quantitatively measure the representativeness of a sample. For example, is there a way ...
1
vote
1
answer
23
views
2 Independent, 1 Dependent Analysis through SAS. Should I create a surface?
I have 12 runs of thermal data that each generate a matrix. I've added noise to my systematic data to simulate my detector. My output for each of these is a 500x500 matrix where the vertical axis is ...
0
votes
1
answer
40
views
Understanding the meaning of random when working with measures repeated at time=1,2,3,4
This stems from a recent exercise in an undergrad course, where we measured average resting heart rate(fH), and fH while holding breath of durations between 0-20s,20-40s,40-60s, etc.
Not only could ...
2
votes
1
answer
13k
views
how to calculate fold change when we have replicate
I have obtained genes with ratios. As an small example you can see my data below
...
1
vote
1
answer
493
views
how to find similarity based on only one column value
I am not sure if it is possible and that is why I am asking the question here.
I have a data looks like below
...
2
votes
2
answers
1k
views
The value of an Effect Size
I calculated a Cohen's d value of d= -2.1.
I understand that there are small, medium, and large effect sizes.
But in my case the d value is negative? Would it still be considered large since abs(-2.1)...
0
votes
1
answer
48
views
What tests to analyze the following hypotheses with nominal data?
I have a set of questionnaire data to analyze the working culture for respondents. (There are four existing cultures; a,b,c and d)
Variables including Gender, Organization, Public/Private Sector, ...
3
votes
0
answers
530
views
Is this simple paired-sample permutation test valid?
I have about 10 pairs of scores, $(x_1, y_1),~ ...,~(x_{10}, y_{10})$, with all $x_i$ and $y_i$ being between 0.0 and 1.0. I'm interested in testing whether the mean difference over pairs is ...
2
votes
0
answers
396
views
Calculating the Chi Squared from combinations of subgroups
Let's say I can calculate the chi squared p-value of different categorical variables and summarise them into a table like so:
Initial Data:
...
1
vote
0
answers
46
views
Sample size when using GPS-trackers to analyze movement of reindeers
If one were to try and analyze the movement of ~2 500 reindeers before and after a (man-made) change in landscape have occured. Specifically how spread out the herd is, both as a whole and if there ...
2
votes
2
answers
786
views
Test for statistical significance in performance variability
I'm analysing data collected from a call centre activity in which agents are calling prospective leads. For each call made, if the lead coverts the call is a success and if the lead does not convert ...
2
votes
0
answers
846
views
How would I determine statistical significance for ad impressions?
I'm programatically adding keywords to bid on. Some keywords will trigger ads and impressions, and some impressions will trigger clicks. Clicks / impressions = CTR (click-through-rate). Clicks cost. ...
1
vote
2
answers
868
views
Compare lists of genes
I have two lists of differentially expressed genes: the list 1 was derived from the universe A of total genes while the list 2 was derived from the universe B of total genes. A number of genes is in ...
5
votes
2
answers
2k
views
Testing if distribution is similar between two groups
I have a variable young that is equal to 1 if a participant is less than 25 years old. I then have a list of of each participant'...
1
vote
1
answer
88
views
What statistical analysis should I use for my study?
In my psych class we were testing to see if groups of men or groups of women would be more helpful in an emergency situation (we are testing for the bystander effect), and we are testing to see if ...
2
votes
1
answer
1k
views
When is appropriate to combine two treatment groups from one study into a composite whole for a meta-analysis?
The treatment groups I would like to combine appear to be virtually the same, at least by generic label for each group, e.g., groups with the same treatment but implemented at different sites or ...
0
votes
2
answers
12k
views
Comparison between Two Groups
One of my demographic variable is age. Age is measured as continues data not categorical. If I want to test differences between two groups to determine whether there is significant difference between ...
8
votes
2
answers
10k
views
How to statistically compare two algorithms across three datasets in feature selection and classification?
Problem background: As part of my research, I have written two algorithms that can select a set of features from a data set (gene expression data from cancer patients). These features are then tested ...
-1
votes
1
answer
750
views
How to provide statistical evidence that an experimental method is providing higher mean percentages?
I performed an experiment using two different methods. The data are percentages and higher percentages indicate a better method. The results were as follows:
...
1
vote
0
answers
288
views
Dixon test for outlier but which one is an outlier?
Following my previous question, I used Dixon test for outliers with the help of Michael Chernick answer. So now I have pvalues for say 10 numbers (basically 10 patients). But I have around 50k pvalues ...