A test (typically of distribution, independence, or goodness of fit) or a family of distributions related to such a test.

learn more… | top users | synonyms (1)

2
votes
1answer
24 views

stats for 2x4 contingency table with both very large and small or zero counts

I have 7000 2x4 contingency tables with count data. They represent a particular position in a genome and the number of times each dna nucleotide is observed at that position in 2 different ...
1
vote
0answers
9 views

Chi-Square analysis after ANOVA and correlations failed to give results

I have a continuous dependent variable and two independent grouping variables of age and gender. Age has three groups and gender two (obviously!). Now ANOVA has shown no differences across both. ...
0
votes
1answer
20 views

Please help me interpret this goodness of fit test

In the game of Bridge, 52 cards are distrubuted randomly among 4 players, each player ending up with 13 cards. I implemented a random number generator using the RNGCryptoServiceProvider form the ...
0
votes
2answers
15 views

Calculating chi-squared values for percentages?

I'm using scipy and I'd like to calculate the chi-squared value of a contingency table of percentages. This is my table, it's of relapse rates. I'd like to know if there are values that are ...
2
votes
0answers
21 views

Visualise significant differences in a contingency table?

I'm working with pandas and scipy, and I would like to find a quick way to visualise unusual values in a contingency table. Say this is my contingency table: ...
0
votes
2answers
32 views

Logistic regression, Chi-square, and study design

I have a study in which I have developed a new predictor (binary) for a disease (also a binary variable). The study has two parts. In the first part, I want to test if my predictor is strongly ...
2
votes
1answer
25 views

Can we run a chi squared test on a normalized function?

Hi I am fit a maxwell distribution and attempt to find the chi squared value in two cases: When the data is normalized. When the data is un-normalized. My problem is that the two ...
0
votes
0answers
4 views

post-hoc multiple comparisons with chi squared using spss v. 22

I am carrying out an analysis using a 4$\times$2 crosstab. I found an overall significant difference but I would like to find if there are significant differences among the 4 groups. Is there a way ...
1
vote
2answers
17 views

Chi-square test for Homogeneity problem (cell count less than 2)

My table of chi-square test for homogeneity has 3x5 cells, 3 samples to a likert scale item. Most cells in the table have a frequency count of less than two, so it is recommended to discard the column ...
3
votes
2answers
112 views
+150

Confidence Interval on a random quantity?

Suppose $\vec{a}$ is an unknown $p$-vector, and one observes $\vec{b} \sim \mathcal{N}\left(\vec{a}, \frac{1}{n} I\right)$. (For example, the sample mean based on $n$ observations of i.i.d. normal ...
2
votes
0answers
23 views

Chi-squared calculation for (nonlinear) model goodness of fit for data with trials

I would like to be certain of how to calculate the $\chi^2$ value for this scenario: We desire a measure of the goodness of fit of a nonlinear model to a data set. The data consists of many ...
1
vote
1answer
59 views

Using chi goodness of fit to test if data comes from normal distribution

The problem gives 50 observations and then asks to check whether the data comes from a normal distribution. For instance if these are your observations then how would you go about testing to see if ...
0
votes
0answers
20 views

What statistical test to use for A/B testing

I'm trying to understand how A/B testing works for a simple 2x2 contingency table. I have found two different types of solutions: 1) Calculate an aggregate probability of conversion assuming that ...
1
vote
0answers
19 views

Pairwise chi-squared tests with Bonferroni correction

I have two categorical datasets, say, $A$ and $B$, which are sparse. I would like to apply pairwise $\chi^2$ tests to a certain categories, which are sufficiently populated (say, have expected values ...
3
votes
1answer
57 views

Pearson's $\chi^{2}$ value?

Pearson's $\chi^{2}$ value is 115.778 and 4 cells (33.33%) have expected count has less than 5. I am confused how to interpret this output. I have a 2 by 6 contingency table. Can someone tell me what ...
0
votes
0answers
28 views

To get the overall significant p value, am I on the right track for LMM?

According to this document: http://www.bodowinter.com/tutorial/bw_LME_tutorial2.pdf I can get the overall p-value of fix effects by comparing models that I would like to know to null model. In my ...
2
votes
2answers
58 views

Test identicality of discrete distribution

Is there a standard way to test whether two vectors were drawn with the same discrete distribution in R? Something like a Kolmogorov-Smirnov test, but for discrete distributions. I think two-sample ...
1
vote
0answers
28 views

How to test for a home bias in a data set?

I'm trying to think how I can test a data set I have, for transactions between buyers and sellers, for a home bias. My hypothesis is that buyers would rather buy from a merchant from their home ...
0
votes
1answer
22 views

Chi square test of association

I wanted to study the distribution of BMI by age. So I randomly made age groups and did a chi square test. Is this appropriate?
1
vote
3answers
88 views

I do not have hypotheses for my research and I have got only categorical data. what kind of data analysis can i conduct? also

I do not have hypotheses for my research and I have got only categorical data. what kind of data analysis can i conduct for correlation between variables? also is chi-square used only for hypotheses ...
0
votes
0answers
23 views

Fitting Model with MCMC?

In fitting a model with several variable I have found extremely useful a method involving the minimization of the Chi Square using a MCMC approach. In particular, I followed this tutorial ...
0
votes
0answers
16 views

Nested Standard Deviations

This is a finance question but most of it is statistics related. A few years ago the Chicago Board Options Exchange created the volatility index VIX, which is really just the 30-day standard ...
5
votes
1answer
86 views

How to statistically compare groups for multiple density plots?

Is there a statistical method to compare these density plots other than ANOVA (MANOVA)? I would like to compare the densities among year within each plot and report which of those distributions are ...
4
votes
1answer
41 views

Is there a PDF for a generalized non-central chi-squared distribution [duplicate]

Is there a PDF for a distribution defined as a sum of squares of random variables pulled from a family of normal distributions with different standard deviation? Is there a way of analytically ...
3
votes
1answer
36 views

How does Pearson's Chi Squared Statistic approximate a Chi Squared Distribution

So if Pearson's Chi Squared Statistic is given for a $1 \times N$ table, then its form is: $$\sum_{i=1}^n\frac{(O_i - E_i)^2}{E_i}$$ Then this approximates $\chi_{n-1}^2$, the Chi-Squared ...
1
vote
2answers
26 views

Missing values in SPSS for Chi-Square Tests

I'm a postgraduate student, doing a accent perception study, this is my first time using SPSS! I'm conducting the above tests on my data, where my participants used Likert scales to analyse the ...
0
votes
0answers
15 views

How To Determine Association Plot in R and p-value

I have created a contingency table and an association plot in R and I am not quite sure how to interpret it. Here is my contingency table: ...
0
votes
1answer
44 views

Conditional or unconditional exact test in R

I have a 2x2 contingency table and i want to calculate if the pair inside is significantly different. i made a matrix like the following named raw_matrix ...
2
votes
1answer
46 views

Post hoc $\chi^2$ test with R

This is a quite simple question but I don't find any good, clear, precise answers: I'm looking for a way to perform post hoc test on a chi$^2$ test. I have 2 variables : var1 : good/fair/poor and ...
2
votes
1answer
42 views

Correct use of Chi-Square?

I am trying to test whether one group is significantly different from another in two different collections of data. I have seen that people tend to use chi-squared or fisher's exact for this ...
4
votes
2answers
82 views

Interplay of Categorical Data

I apologize if my phrasing is un-educated, I don't have much of a stats background. I'm struggling to find info answering my question because I lack the terminology to accurately describe it. Let's ...
0
votes
0answers
7 views

chi-squared feature selection

I have a feature vector of size 250 x 35. That is I have 250 images and each image has 35 features in it. I need to do chi-squared test to get the most significant features out of it. anyone know ...
0
votes
0answers
17 views

how to test if a proportion of alleles is different between conditions?

I am in doubt about which type of test I could performed on my data. I have a data frame of the following type: contig, pos, A1, A2, Ctrl_A1, Ctrl_A2, Treat_A1, Treat_A2 comp1293557_c0_seq1, 284, ...
0
votes
0answers
33 views

Chi-squared test with scipy: what's the difference between chi2_contingency and chisquare?

I'd like to run a chi-squared test in Python with scipy. I've created code to do this, but I don't know if what I'm doing is right, because the scipy docs are quite sparse. Background first: I have ...
1
vote
1answer
32 views

Cooccurence of Two Categorical Variables

I am trying to calculate if there is a dependence between two categorical columns, or a significant cooccurence of two categorical variables. Let's say I have columns A and B, and and out of 200K ...
0
votes
0answers
28 views

Web Videos that can provide me with a better understanding of statistical concepts

I have an exam coming up and I would like to know are there youtube videos/playlist or any videos online that can explain the following concepts below in a simple manner. The concepts are: ...
0
votes
1answer
13 views

What is the best way to quantify concordance of two tests?

I have two different medical diagnostic tests, both test the same condition (binary outcome). The condition in question is rather vaguely defined, so they don't always agree. What would be the best ...
1
vote
1answer
102 views

$t$ test vs $\chi^{2}$ once sample is split into two groups?

I would appreciate some guidance regarding the use of a t test vs $\chi^{2}$. I am looking at some small set of demographic data (n only 13). I have divided up the sample into two sets, those with ...
1
vote
0answers
28 views

Best proportions test based on counts (accuracy, distribution, etc)

I'm trying to compare two sets of counts over totals. For example, subject 1A will have 40 out of 600, and subject 1B will have 3 out of 20. How do I compare these proportions and counts while taking ...
1
vote
1answer
29 views

What does y argument do in chisq.test in R?

The chisq.test function in R includes a y = argument, which is to NULL by default. The help ...
2
votes
1answer
25 views

Is there a significantly different number of people between groups?

How do I estimate whether a given number of people across groups (say, 72 people in group 1, 95 in group 2 and 70 in group 3) significantly differs from a random distribution of people across groups? ...
1
vote
1answer
22 views

Appropriate Statistical Test for multiple groups

I have a question regarding which test I should run on some data. I have small groups of people who answered questions. The answers to these questions have been classified as correct or incorrect. ...
1
vote
1answer
94 views

Comparing large categorical data sets with low or zero counts

I'm dealing with a biological feature which can be classified into $2^{20}$ categories. I also have two pretty large data sets of 1 and 3 million entries. Actually, only around 30 thousand categories ...
2
votes
0answers
22 views

How to approximate error on Chi-Squared Fit when bin counts are zero

I am using a galaxy image simulator that provides a 2D histogram that has the number of photons per pixel (bin) $N$. I am currently using a least-squares residual: $\sum_{bin}(f_{data}-f_{model})^2$ ...
0
votes
4answers
43 views

Two groups are significantly different? Test to use

I have two groups of discrete data (integers): ...
0
votes
1answer
27 views

prop.test: correcting for large number of observations

This is not really a coding question but more of a statistical question. I'm doing a proportions test on multiple proportions for many subjects. For example, subject 1 will have multiple proportions ...
1
vote
0answers
52 views

Different p-values between Wald Z and Wald Chisquare

I have used lme4 for mixed effects models of reaction times and accuracy rates. I could not use lmerTest because the type of model I was using are not yet implemented there (problem with predictors ...
1
vote
0answers
25 views

Overly-sensitive goodness of fit measure: where did I go wrong?

I'm using the chi-squared goodness-of-fit measure to evaluate instances of a fairly complicated model, but the evaluation is unbelievably sensitive to small variations in the model parameter values. ...
4
votes
1answer
123 views

chi square test or Z test?

SO I have an outcome from a biological experiment, where I have counted the number of dead cells upon a mutation. For example, in once case - out of 120 cells we saw 16% of the dead cells, but our ...
2
votes
1answer
85 views

Proper analyses for 2x2 contingency tables

So I have multiple questions about the different types of analyses that can be used on a 2x2 contingency table and when different analyses should be used. To open, I'll note that this stems from my ...