Questions tagged [count-data]
Count data are non-negative integers representing whole amounts.
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Equidispersion Property - Why and Where
I've often looked at count data models over the years. And like a lot of statistical models, they can be used/abused in cookbook style.
Identify equidispersion -> do X model (Poisson).
Identify ...
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Best test to compare cell population counts across patient groups
Given a data frame structure similar to the following:
...
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Comparing a paired count data
I have a group of patients who are subjected to treatment A. I wish to compare the number of events/patient before and after the treatment. The duration of follow up of before and after therapy is ...
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How do you sample from a Poisson distribution when the observed count is zero?
I have some data showing the count of deaths in a population. The data are stratified by age. For example, the data might show that at age 40 there were 30,000 years of observation and 300 deaths.
In ...
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Distribution model for Multiple-choice Data?
I am running an experiment where I am testing the effects of three interventions (A,B,C) and measuring participants' performance via a multiple choice test with 5 questions. To perform hypothesis ...
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VAR models: Effects of sparsity and magnitude disparities on VAR dynamics and possible solutions
In a VAR model involving two (or more) time series, if one series has sparse data with low counts, while the other series has lower sparsity and higher values, are there any statistical or technical ...
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Overdispersed and zero-inflated count data
I have a dataset with social media posts and like to predict the number of likes a post receives.
So I fit a Generalised Linear Model (GLM). I am relatively new to GLMs but find them super cool. ...
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Count distribution in which the mean is equal to the standard deviation?
I have a data set with counts that exhibit the sample property that
$$\hat \sigma_x \approx \bar x$$
which is to say that the sample standard deviation (with Bessel's correction) appears to ...
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Do I need a hypothesis test to compare two populations of complete annual count data?
I would like to compare the total number of public M&A transactions observed in two separate years (e.g. 2021 vs 2022). Given the data set for each year is complete (i.e. a population), can I ...
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Is the variance a suitable measure of variability in this context?
A rather basic question, prefaced by the fact that I know just enough about statistics to be dangerous.
I work with Air Force Technical Training. I am trying to compare the ebb and flow of students ...
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How to use partial correlation on compositional (counts) data? (e.g., as described in Erb et al. 2020)
I've read through this paper: https://www.sciencedirect.com/science/article/pii/S2590197420300082
Which introduced me to the concept of partial correlation. I typically use Proportionality when ...
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Are 0s real or fabricated? [closed]
I am working with data from different brands where I have how much the different brands were bought for a particular day over the period of 1 year. However, I know beforehand that some of the data is ...
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Direction of main effects in cox regression and negative binomial regression changes when adding variables
For a research I am conducting I am looking at the effect of two categorical variables (dummy with values 0 and 1 for each group) on the speed and quantity with which customers make future purchases.
...
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273
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Poisson regression with small denominators/counts
I have daily data on surgery cancellations for about six months and would like to examine the bivariate associations of several factors and surgery cancellations.
Each day there are variable number of ...
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What type of regression analysis should be used for this combination of count data?
What type of regression would be best suited to do a multiple regression analysis with $E$ as the dependent variable? Is using a binomial regression okay? Thanks for any suggestion.
For each of my ...
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Statistical significance of counts per month
I have a dataset of events over time. Commonly, we are interested in how many events per month and how many events per year. Here is a dummy dataset:
Year
Month
Count
2019
Jan
2
2019
Feb
1
2019
...
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Analyzing pick, group & rank data
Participants completed a survey containing a pick, group and rank question. In detail, they were provided 16 items and asked to choose the ones that are relevant to them. Afterwards, they should rank ...
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Which test to use for (repeated) count/proportional data to test for differences within a categorical variable?
Background information
Using different machine learning models, I predicted three different behavioural categories in cats (active, inactive, maintenance). I then created a dataframe that contained ...
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How to find overall data trends from count data across multiple subjects
I'm working with a dataset on ecosystem invasion, where individuals of an invasive species are "colonizing" a specific species of tree, tracked over time. Count data were collected 4-6 times ...
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Regression Model for a Ratio Outcome with No Assumed Distribution
I am conducting a study on patients with small follicles in their ovaries, diagnosed by ultrasound. Different drugs are administered to these patients, and they also have varying hormonal levels. ...
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counterfactual prediction in country-year data
I'm trying to explain a time-varying country-year count variable of an event (Y) with both time-varying and time-variant variables (X); I have data of a around 100 countries for 20 years (2000-2020). ...
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How to calculate the error on the ratio of a counting experiment?
In an experiment I repeat some task $n$ times and count how often the task completes successfully. This gives the number $m$. Therefore the success ratio is
$$
r = \frac{m}{n}
$$
To calculate the ...
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How to normalize dataset with mixed data (continuous and count)?
I am trying to determine what procedure should I use to feature engineer the most descriptive possible dataset to predict a binary outcome. The dataset has variables that are count-valued with ...
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Comparing Defects per Volume
Let's set up a toy problem. Say I make a vat of soup every week. Different kinds of soup, different volume each week (e.g. 50 gallons, 46 gallons, 10 gallons, etc.) and sometimes there are flies in ...
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Error when using R zeroinfl on negative binomial count data model
I want to model number of plants in 12 different areas.
Each area is divided into smaller plots of equal size for all areas. The number of plots between areas vary (31 for the smallest area, 500 for ...
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Regression Model for a Ratio Outcome with Count Variables as Numerator and Denominator
I have a dataset where each row corresponds to a country and contains independent variables such as "per capita income" and "mean education status." Additionally, there are two ...
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Hypothesis Testing for Paired Count Data
I have the following data:
For a group of patients, the number of hospital visits in a 6 month period both before and after receiving a treatment has been measured. I wish to demonstrate that the ...
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56
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How to deal with non-normally distributed data?
I have a proportion data (0-100%, or it can be count data 0-20) that is not normally distributed. The hist graph in R shows:
I have tried many ways to transfer data (log, coxbox, ranktransfer), but ...
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Zero inflation formulas do not improve zero inflated model (GLMM) [closed]
I'm a student trying to adjust a count data GLMM to zero inflation using function glmmTMB.
Model family is nbinom1 family (better AICc compared to nbinom2 and poisson).
My data contains about 20 % ...
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101
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Chi-Squared Test of Association Equivalent for 3 Categorical Variables and Observed Frequency
EDIT: SOLUTION FOUND, SEE BELOW QUESTION
I'm an undergrad writing a very simple lab report in which I'm analysing some data on observed numbers of birds at two different study sites. The exact data ...
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GLMM on temporally correlated count data from a designed agricultural experiment
I have carried out a designed agricultural experiment with two treatments and recorded the effect on the abundance of a pest insect on three dates. The field experiment was divided into four blocks ...
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Analysis of spatially correlated count data from a designed agricultural experiment
I have carried out a designed agricultural experiments with two treatments and recorded the effect on the abundance of a pest insect. The field experiment was divided into four blocks with two plots (...
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1
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Should I be concerned about outliers in NB GLMM with an offset term?
I'm working on a negative binomial model for count data. Unfortunately I can't provide a more detailed description because I wasn't explicitly allowed to. All I can say now is that the data is about ...
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What are suitable statistical approaches to examine temporal variation of species abundance/ community composition across multiple sites?
I'm looking for appropriate types of analysis for a data set that contains counts of different crab species across 4 sites with 3 replicates per site (12 in total) over a time period of 1.5 years - 5 ...
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Binary logistic regression for count data in set of trials
My question is it correct to use binomial regression when the outcome is count data with a fixed upper limit and trials are different tasks. In my experiment, I count the number of consequentialist ...
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Is the count regression model valid in this use case?
I was doing a project where my target variable is a count variable. So naturally my mind went to Poisson regression, but upon further inspection, any identical set of
my explanatory variables can ...
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41
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Compare proportion of value between groups in R
I have 4 groups in which I have for each 7 days
...
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How to measure the similarity of frequency of categorical data
Sorry if this is a really simple question but I'm new to this and wondered if there's an easy way to do what I'm picturing.
Imagine I've got a bunch of people and I'm asking them what they've eaten in ...
2
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1
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116
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Use count data models when the dependent variable is a ranking (with panel data)
I am currently writing a Master Thesis about the relationship between academic freedom and World University Rankings (such as ARWU, Times Higher Education, etc). I am using panel data.
My dependant ...
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How to use weights in the right way?
I have a dataset and in the description is written <<In order to improve the representativeness of some segments of the population, the variable pesofit (...
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What is the appropriate statistical test for count data with uneven groups and uneven sampling effort?
I have a problem I've been going over and over for weeks and I'm not sure what statistical test to use for my analysis. I'm planning to execute the analysis in R, so any demonstration of the relevant ...
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Assessing whether the given code for Poisson regression model is apt for the scenario and steps needed when residuals are not normally distributed
I have two subjects: one was vaccinated, one was not. 19 different behaviours were recorded at each vaccination stage (5 stages in total). I want to know if the vaccination worked in reducing certain ...
2
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1
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118
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GAM: predictor range varying across groups. Should data be transformed?
I am modeling the seasonal occurrence of a species at different sites (count data). I am specifically trying to identify potential drivers of the seasonal pattern. To this end, I have selected a ...
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Predicting outcome with ordinally, continuously or linearly related predictor variables
I am attempting to predict the number of chicks that will hatch from a group of eggs stored in a box. My predictor variable is the count of the eggs based on their size, such as "THE NUMBER OF ...
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How to conduct a statistical analysis for a regression model when different independent variables have ordinal or continuous relation
I have a question about analyzing a regression model with a count type, 1 dependent and 10 independent variables that are in ordered fashion. For example, I have a dataset containing information on ...
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How to analyse count data with a single sample?
I have one sample where participants saw ten images, and I am interested in whether there is a difference in which image got noticed first. So I have count data for this where each image will have the ...
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Conducting a regression model with beta coefficients dependent to each other in a nonlinear way (My different independent variables are ordered)
I have a dataset of 1000 previous contests in a giveaway show where the contestant earns a random number of boxes named from "one" to "ten". The boxes contain either 1 or no gift. ...
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What statistical analysis to run for continuous variables and count variables in SPSS?
My study for my Bachelor Thesis consists of 3 independent variables and one dependent variable. I want to analyze whether cooperative attitude predicts a change in defending behavior against bullying ...
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What regression should i perform in order to obtain an R-squared or pseudo R-squared with my data properties?
I've got a rather hard question concerning my regression.
My data has the following properties.
Dependent variable is count data and is overdispersed and consist of repeated measurements within ...
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67
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How to transform count response variable including zero values to non-negative values for fitting a GAM analysis?
I am trying to fit a GAM model that the response variable is count var (species richness) and the predictor variable is elevation. In my dataset there are some zero values for richness in some ...
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