All Questions
Tagged with statistical-significance chi-squared-test
300 questions
5
votes
2
answers
6k
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Chi Square versus Poisson distribution
In a study which analyses the effect of Lithium on suicide rates, the results were the following:
Placebo group: 3 suicides in 83 patients
Lithium group: 0 suicides in 84 patients
My first approach ...
2
votes
1
answer
85
views
How to infer on a human intelligence task about selecting the best option
I have a human intelligence task test which tries to get the best option from a set of options tested against a control group.
The test consist of:
Suppose we have a control group of options, lets ...
- 81
3
votes
2
answers
57
views
How to tell a method is improving the detection of a disease?
We have two methods, A and B, for detecting a disease. Out of a 1000 samples with unknown prevalence, A detects 100 samples (10%). On the remaining 900 negatives, we apply the additional method B, and ...
- 7,697
1
vote
0
answers
56
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Test for positional amino acid enrichment
I have a question about which statistical test to use for a particular research question. I am studying protein binding motifs (amino acid sequences that other proteins bind to), typically these ...
- 11
2
votes
1
answer
113
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What to do after a chi-squared test for 2 way table?
Suppose I have the following 2 way table and I perform a (Pearson) chi-squared test on it. With the null hypothesis: children's goals are independent of gender.
...
- 37
3
votes
1
answer
135
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Significance test for categorical variables
I'm working on analyzing a dataset with the following structure:
...
0
votes
1
answer
62
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understanding chi squared test: is it appropriate on the following problem
I am trying to get my head around the Chi squared test. Let's say I have collected data on two different days:
day A: the weather was good and I sold X ice-creams
day B: the weather was bad and I ...
- 147
0
votes
2
answers
2k
views
Goodness of fit (chi-squared) for non-exclusive categories
I'm analyzing some data, which is sorted into some categories, and would like to compare my results to a hypothetical distribution of those categories. I feel like the chi-squared test for goodness of ...
- 1
0
votes
0
answers
13
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Comparing initial symptoms to a diagnosis
I have a small dataset of 80 patients with a diagnosis of 3 types of cancer: AML, ALL, and CML. They each come to the hospital with one or two symptoms: Fever, Diarrhea, or both. They all eventually ...
- 101
2
votes
0
answers
46
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Statistical test for comparing cutoff values in independent samples
A binary diagnostic test currently uses the same cutoff value (level of biomarker) for males and females when determining disease vs non-disease (D+/D-). However, I suspect that the level of biomarker ...
- 21
1
vote
2
answers
3k
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prop.test or chi squared test on count data with 3 groups?
I have some count data pertaining to number of events observed among independent trials in 3 groups of an experiment:
...
- 125
0
votes
0
answers
56
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Comparing Between Multiple Results from Separate Chi-Squared Tests of Proportions in R 2
I am curious about the appropriate statistical test to compare the results from a chi-squared proportion test in R.
In the below code, using a chi-squared proportions test in R, it is shown that the ...
- 31
1
vote
0
answers
18
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Independence on only some cells of the contingency table
I have two discrete variables with three values each, A,B, and C for one, and D,E, and F, for the other (for around 500 objects).
I am only interested to reject independence in three cells of the ...
6
votes
3
answers
1k
views
Significance of relationship between sex and bachelor's degree or higher (2017 U.S. labor force, ages 25 and up) (disparity, difference)
Reports and webpages like the following prompted this question: "Women Now at the Head of the Class, Lead Men in College Attainment" by Kurt Bauman and Camille Ryan, October 7, 2015, United ...
- 69
0
votes
1
answer
676
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Checking independence of A/B/C/... test results using Python
Assume I collected the following results from an A/B/C/D/E test:
...
- 279
0
votes
1
answer
39
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testing significance in a specific setup
Collective wisdom is desperately needed! I need to understand if some kind of significance testing is applicable here, and if that is the case - which test.
The data collection was devised as follows:...
0
votes
0
answers
635
views
Calculate representative value for data
Assume there are ten data with values $a_1$, $a_2$, ..., $a_{10}$ each with different non-symmetric errors. The problem confronting me in brief is, to combine the 10 results $a_{i}$ and their ...
- 103
1
vote
1
answer
1k
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Check for equal slopes with Chi-Squared test
I have the following distribution of counts where blue represents blue shoes, red represents red shoes and green represents green shoes. Though the total sales numbers differ I want to check if the ...
- 295
1
vote
1
answer
256
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Statistical Significance Test (Genotypes and Race)
I've been trying to think of the best way to approach testing for associations of genotypes (i.e. D/D, D/I, I/I) with ethnicity (i.e. African Americans, etc). Specifically, I would like to test ...
- 13
1
vote
0
answers
45
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Chi Test to compare the volume distributions of 2 samples
I have 2 samples and i want to check whether their distributions are similar (or not).
The samples are distributed in the following way (they are banded into 'scores'):
How do i check the whether ...
- 61
-1
votes
1
answer
227
views
Which statistical test to use for non-square contingency tables
I have data before treatment encoded with numbers 1 or 2 which are two different types of a disease. The data after treatment are encoded with numbers 0,1 or 2 where 0 means that the patient has ...
- 131
2
votes
1
answer
108
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Paired t-test, t-test or chi-sqaure test?
I want to compare two types of designs. After showing them the images of two designs, I have asked the user (7 questions), which design they like most (A or B)? The user can chose only 1 out of 2 ...
- 31
0
votes
1
answer
82
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Sentiment analysis, are my samples significantly different?
I have extracted data from a reviews website. I have created a dictionary with all words that appear in the reviews and corresponding number of counts.
I have then spit the reviews into two samples: ...
2
votes
0
answers
357
views
Statistical Significance of the "Cost per Conversion"
I am trying to optimize our AdWords ads and running some statistical tests. I use a chi-squared test and Fisher's exact test for conversion rate data; for example the click-through-rate (CTR) or the ...
- 21
1
vote
0
answers
41
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Chi Square Tests throws varying p-value results [duplicate]
Suppose I have a random number generator and I want to check with a Chi Square Test whether its pdf is uniform or no. I can write a script that does that and I will run it several times. To my ...
- 111
0
votes
1
answer
285
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How to test significance between rates of occurrences
Without going into domain specific information, I have a data set in which I'm testing the rate of occurrences of an event like so:
Event 1
# of trials: 378
# of occurrences: 109
# of occurrences ...
1
vote
1
answer
29
views
1-sided vs 2-sided general M*N independence tests like Fisher exact or $\chi^2$ tests
What does the 1-sided vs 2-sided distinction mean for general $M \times N$ independence tests like Fisher exact, $\chi^2$ or $G$-test?
Which makes more sense?
What is the "negative" side in these ...
- 651
2
votes
0
answers
1k
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Cross-tabs: Can residuals in table be interpreted if chi-square statistic not significant?
I'm examining a series of 2 x 5 cross-tabs / contingency tables. I have taken the approach of: (1) determining whether the chi-square statistic (test of independence) is significant (i.e., p < .05),...
- 21
0
votes
1
answer
418
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What would be appropriate test to compare two lists of dichotomous variables?
Colleagues, can't wrap my mind on simple question, please help!
I have two products and list of their attributes. My respondents make an answer which product on each attribute they prefer. Finally ...
- 277
1
vote
2
answers
3k
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Tests of significance, correlation vs chi-squared [closed]
I am comparing two ordinal variables along a Likert scale. From previous help received on this forum, I have decided to use the Spearman Rho for my correlation statistic. My next question is how to ...
- 39
0
votes
1
answer
271
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Understanding the significance between observed and expected values in contingency table
Below is a table which I would like to understand the significance of each specific cell in terms of "is what I'm observing actually statistically significant"? I am aware of the Chi square test but ...
- 105
0
votes
0
answers
40
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What should the relationship between significance and correlation be? [duplicate]
Is it possible to have a very significant Chi-squared test, but a terrible correlation (I'm talking around 0.2)??
- 39
2
votes
2
answers
1k
views
Ordinal vs Ordinal, correlation vs significance
I am comparing two ordinal variables (i.e., two independent Likert items). I've used a chi-squared test to test significance of a relationship between the two, and a Pearson correlation (I'm expecting ...
- 39
2
votes
1
answer
7k
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Statistical test for comparing two frequency distributions expressed as arrays (buckets) of values
I am looking for an appropriate statistical test that will compare two frequency distributions, where the data is in the form of two arrays (or buckets) of values.
For example, suppose I have two ...
- 3,630
2
votes
1
answer
890
views
Comparing to paired categorical variables
I have a variable X with 100 samples, each is 1 (success) or 0 (failure)
Thereafter I perform somekind of manipulation, and recollect data, so I get 100 more samples that are 1 or 0,
How can I check ...
- 57
0
votes
0
answers
37
views
How to deduce "statistical significance" given error and fit deviation
I have a best-estimate value for some quantity $H$, along with uncertainty $\delta H$. I am told that the best-estimate $H$ was determined by fitting some unknown function involving $H$ and an ...
- 199
0
votes
0
answers
866
views
Two-sample test for discrete data
I want to validate that two samples of data with ties do not come from the same underlying distribution. The data itself describes the repair cost of cars and has a continuous value range. My solution ...
- 157
1
vote
0
answers
43
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Would the 2 way Chi Square test be appropriate for this scenario; If not, what test is? [closed]
The test hypothesis is this:
Does a student’s gender have a greater influence on their choice in
whether they study data science as a core topic; than other
demographic/variable factors?
The ...
- 11
0
votes
1
answer
52
views
Comparing groups with different sample sizes
I have some data about network outages in two companies, by the type of machines they have:
...
- 143
0
votes
0
answers
53
views
Comparing percentages
Question:
I am trying to compare the percentages I have accumulated from a research study. Say that I have collected data on a certain group of patients, all having the same diagnosis. Then I divy ...
- 1
0
votes
0
answers
398
views
Categorical Data Analysis (using SPSS)
Searching for behavioral differences between two groups of horses is my main research goal. All the recordings (as I mentioned in the title) are consisted of categorical variables (nominal in most ...
- 33
0
votes
1
answer
126
views
How to estimate statistical significance of the difference between two groups
I need to be sure that the difference between estimations of the percent of returning visitors to a web page in two groups is not just a random difference. I have the following data:
...
- 11
1
vote
0
answers
207
views
Help with preference test
I need some help choosing the statistical test to calculate if the bee families have a preference for a straw size.
To summarize the project, I am looking at 4 bee families
Osmia-Megachile-...
- 11
4
votes
1
answer
1k
views
Statistical significance of the residual in a particular cell in a Contingency table. Extrapolation from a Sample to the Population
The statistical significance of the overall residuals (expected - observed counts) in a contingency table can be tested through chi-square.
However, is a way to test whether a residual in a ...
- 947
2
votes
0
answers
371
views
Testing for a significant difference between 2 groups
Question 1
Two equally sized patches of the night sky are examined:
Patch A contains $100$ stars
Patch B contains $110$ stars
Is there a significant difference between these two patches of night ...
- 451
2
votes
1
answer
696
views
How do I test for differences in cost per acquisition (CPA) in an A/B test?
How would I go about testing for differences in cost per acquisition (CPA) in an A/B test?
I'm a huge novice and am unsure if I would use some kind of t-test or chi-square test (or neither) to ...
- 21
4
votes
0
answers
21k
views
Comparing two percentages
How would I go about comparing two percentage figures from two different sample sizes? For example:
Sample 1 - 10% (220,510 out of 2,205,100) of respondents answered "yes",
Sample 2 - 31% (12 out ...
- 41
1
vote
0
answers
79
views
coincide by more than chance?
I have an issue where I want to see if two events may coincide by more than chance.
For instance given the following data I may hypothesise that "Alice" and "Bob" come into the office together more ...
- 215
2
votes
1
answer
164
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Chi-squared Test and Data Representation
I have a question with applying Chi-squared tests to a given set of data. Let's say that my data is numbers of different-colored MM's in a bag.
Suppose there are 6 red, 4 blue, 8 orange, 2 green, 10 ...
- 123
2
votes
2
answers
3k
views
Calculating chi-square and p-value
I'd like to test people's preference on model A against three other models B,C,D.
I asked 5000 people on crowd sourcing to rate all 4 models (thus, there are 20,000 ratings overall) in the scale of 1 ...
- 169