Count data are non-negative integers representing whole amounts. When such data are the dependent variable in a regression, Poisson or negative binomial regression may be appropriate methods. One common problem is "zero-inflation" (where the proportion of zero values is greater than predicted by a ...

learn more… | top users | synonyms

0
votes
0answers
9 views

Estimation of Integer Valued Autoregressive INAR(1) by MLE

Please guide me how to estimate Count data time series Model Integer Valued Autoregressive i.e INAR(1) by Maximum Likelihood Method.
0
votes
0answers
17 views

Zero Inflated Poisson or Negative Binomial Regression model in Panel Data

I am using the Stata version 13.1. My data is count in nature and also it is a balanced panel. However, my data suffers from the problem of excess zeros and also suffers the problem of overdispersion. ...
0
votes
0answers
16 views

maximum likelihood for count data [closed]

Can maximum likelihood estimation method of parameter estimation be used in categorical data? I was looking for some examples of it. What other parameter estimation techniques work for this kind of ...
2
votes
0answers
37 views

Approximate normality of distribution of counts in contigency table

I seem to be struggling with lack of basic understanding of some important concepts. This is a question to the answer of @Glen_b in this post: Warning in R - Chi-squared approximation may be ...
1
vote
1answer
35 views

Searching for signal in a somewhat noisy landscape

I'm trying to implement a system to identify regions of high signal content in the presence of a noisy landscape. By high signal content, I simply mean intensity values significantly above background ...
1
vote
0answers
30 views

Predicted number of events from xtnbreg, fe make no sense

I am trying to compute the number of predicted events from a fixed effects negative binomial regression model in Stata. I run the model first using random effects, then using fixed effects, and ...
3
votes
0answers
41 views

Quasipoisson or negative binomial glmm with differing dispersion by group

I have a set of count data, which look something like this: ...
0
votes
1answer
37 views

What transformation should be carried out if the count is non-integer in poisson glm in r?

My data is like this: person final sex 1 34.20 1 2 2.00 0 3 15.58 0 4 18.00 1 5 50.06 1 I am fitting ...
0
votes
0answers
21 views

Correlation to use for non-scale data( counts)

In our college we run some extra non-required sessions that we hope help the students. To decide whether they help, I wanted to correlate the number of sessions attended with the cumulative gpa of ...
2
votes
1answer
22 views

Suggested method for estimating door counter stats when data is lost

I'm wondering if you have any advice about a methodology to use to estimate "door counter" stats (i.e., an automated count of visitors to our organisation, based on "break beam" door counters ...
0
votes
0answers
6 views

GLM to asess differences between two treatments with only one IV

I have some data that I've collected in the field while running a trial where some sites (random 50%) received a treatment and the others did not. The dependent variable is the total number of baits ...
0
votes
0answers
18 views

Which means difference test to use?

Currently, my data is count data and I am analyzing it in Proc Glimmix in SAS. My data focuses on how many times birds from two treatments performed stand, sit, forage, ect.... So it basically looks ...
3
votes
3answers
181 views

How can you tell if a yearly increase in population is statistically significant?

I have daily data for two years consisting of "number of sightings" each day. Is there a way for me to test whether the data for year 2 is "significantly" higher than the first year? I know the ...
2
votes
1answer
30 views

Can I use glm with Poisson family if counts data are treated as density?

Imagine you have data of birds counted in an area - let's say, you count 18 birds in a surveyed area of 1,3 km^2. Imagine you relate this counts to 1km^2, so that you have 13.9 parrots per km^2. ...
1
vote
1answer
28 views

How to correlate count variables that are nested / non-independent?

Above is a snapshot of a subset of a larger dataset, N=61. Group is the group number, Iterations is indicating the ...
0
votes
0answers
40 views

Modelling count data: mean-variance relationship

I have fit a poisson, quasi poisson, and negative binomial model to some count data. To ensure that I have valid models, I am checking that the following assumptions are satisfied: No ...
7
votes
3answers
196 views

Modelling count data where offset variable is 0 for some observations

I'm trying to help a student of a colleague. The student observed and counted bird behaviour (number of calls) in an experimental setup. The number of calls attributable to a specific observed bird ...
1
vote
0answers
33 views

Which significance test can be used in this instance? - paired, non-normal means

I have a data set of behaviours for a herd of captive elephants which I have attempted to quantify to compare for statistical significance, i.e., if a behaviour is performed once during an observation ...
1
vote
0answers
51 views

Count Panel Data Event Study

Can anyone suggest a lecture/paper/textbook that covers an event study (eg. exogenous policy change) using count time-series (or penal) data? Or alternatively, just a general guideline as to what ...
1
vote
0answers
30 views

Poisson regression with underdispersed and truncuated/censored upper bound

I'm analysing data from an experiment in which participants, over a number of trials, were presented with 8 boxes - 7 containing gold coins, and 1 containing a pirate. Their task was to open as many ...
1
vote
1answer
57 views

calculation of variance

Hi I have a question regarding calculation of variance of survey results. Consider the following example. If 5 (x) people answered a survey which consists of 3 (y) yes (1) or no (2) questions. You ...
4
votes
2answers
106 views

Testing if frequency of event occurrences over week days is uniform

I’m trying to figure out if there’s a calculation that can be done to show you have enough data to draw conclusions on trends within the data set. I have made an observation on a class of equipment ...
3
votes
2answers
50 views

Can categorical variables be treated as count data?

In a questionnaire study, I asked for the frequency of certain behaviors using a 5-point scale. Originally, I planned to treat it as categorical, however, distribution of the answers (N=1000) turns ...
0
votes
0answers
108 views

Negative Binomial Regression model; algorithm did not converge

I am using R to run some negative binomial regression models. For model 1 I have the number of network in-degrees as the dependent variable, and Twitter followers, friends and number of Twitter ...
2
votes
1answer
21 views

Estimating better performing variation with unkown sample size

Scenario: We are in the app business and trying to optimize for downloads in the app store. Things like the shown screenshots, the text, the icon etc. can be changed and will have an influence on the ...
0
votes
0answers
9 views

What test to run for one group with two binary categories

I'm not sure what is the appropriate test for this simple question: I have 1858 observations in two different conditions and for each observation there are two possibly outcomes: IN or OUT. My counts ...
1
vote
0answers
20 views

Negative Binomial Anscombe Residuals

I need a help :) I'm working on a Generalised Linear Regression model, using the 'so called' NB2 model, in other words I'm using the Negative Binomial regression for count data. I would like to graph ...
1
vote
0answers
15 views

Help in determining prediction accuracies over the life of a customer

I have been tasked with determining the accuracy of some data, however my statistical knowledge is weak and I am hoping to be pointed in the proper direction. For a customer, we have a series of ...
1
vote
1answer
34 views

Which models for suitable for integer values of independent and dependent variables

The data set has independent and dependent measurements that are events, and can be counted. What input / output models are appropriate for integer values? So far I've tried linear regression, and ...
1
vote
0answers
14 views

Correlation between offset and predictor in count data

I am fitting a Poisson model that requires an offset term to account for sampling effort. However the offset term is highly correlated with one of the linear predictors that is central to my ...
0
votes
0answers
32 views

R implementation of Zeger's parameter-driven (latent process) approach to time series regression with count data

For time series regressions with count data, Poisson-response with log link (i.e. GLM) is widely used. However, such models often suffer from serial correlation. One approach to handle was introduced ...
5
votes
2answers
65 views

Appropriate method for determining difference between means?

I'm looking at the calling rate of bird species when prey availability is altered. So there are two groups, a control (no manipulation) and experimental group (where prey has been increased). I'm ...
0
votes
0answers
17 views

What test should I do to evaluate overlap between two sets of count data

I have one set of data. This set A has about 5000 members and they are divided in 8 subgroups, but each member has also a membership in one out of 24 other groups (let's call these set B). What I want ...
2
votes
0answers
35 views

Does N-1 correction for Pearson's Chi-Square apply to r x c tables generally?

Campbell (2007) recommended what he called the "N-1" correction for chi-square tests performed on two-by-two contingency tables. He described the correction as: "the K. Pearson chi-squared test ...
1
vote
1answer
248 views

How to interpret ANOVA output when comparing two nested mixed-effect models?

I've got two models (all variable are count variables): ...
0
votes
0answers
23 views

Simulation of CI of amount of values in different intervals by adding noise to original data

I am having a hard time trying to solve this problem, so maybe some of you guys can sort it out. I have a large data set containing a value describing the thermal comfort in buildings called PMV. The ...
1
vote
2answers
144 views

Alternative for Fisher's exact test for count data in table bigger than 2x2

I have count data on different languages from comparable corpora. It looks something like this, where the counts give the number of clauses with that particular word order attested in each language ...
0
votes
0answers
23 views

Good way to categorize count data?

I want to use some count data to train a classifier. The count data range from 0 to 400 something. There are a bunch of smaller counts (0's and 1's). I wonder what would be a good way to categorize it ...
1
vote
0answers
137 views

Count data in a Structural Equation Model

I am currently trying to fit a structural equation model (SEM) on a certain dataset using R (lavaan package). Some of the most important variables in my model are count data (abundance of different ...
0
votes
0answers
18 views

What is the number of “observed data” in a multivariate HMM

I am trying to calculate BIC scores for a couple of models with different states. (See general question 1 and a more specific q2 - no answers in either). I've done my own research a little bit and ...
1
vote
0answers
21 views

How to compare a one-day count against a historic mean to identify an external change

A few months ago a client's website had some good press and their daily site visits spiked. Now, every time their traffic shows a bump, they think something external has caused it to happen. I'm ...
1
vote
1answer
167 views

How to compare count of two groups?

I have a two groups of data - 1/ All data and 2/ Selected_season, which is only some subgroup of all data. I want to find out: a/ if proportion of BM, HB, etc. groups is the same in All data and ...
2
votes
2answers
47 views

How to do smoothing of data with low counts?

We are a facing a problem of fluctuating shares for each week for the products we are studying due to low counts. e.g. If we have 4 products and for each one we have say like 5,8,3,6 details and we ...
1
vote
1answer
88 views

How to model a count dependent variable with upper limitation

I have a dependent variable, which have 0, 1, 2, or 3 for its value. I asked participants to choose three items and coded 1 if it is in a certain category and 0 otherwise. I add the three binary ...
3
votes
1answer
275 views

ANOVA and Count/Percent Data

I'm just starting to work with some count data and I'm still trying to understand some of the complexities of it, so any help would be greatly appreciated. First the simple version, and then the ...
0
votes
1answer
36 views

Statitical test on count data

I have a questions regarding a statistical analysis of a biologic experiment. In the experiment I have collected imaging data on the duration of contacts between immune cells. We have compared two ...
2
votes
2answers
97 views

Best distribution to handle a ratio of counts as a response variable

A quick statistics question (apologies for the added biology): I have two sets of counts (for the expression of two different isoforms of a particular gene), and to generate the response variable in ...
0
votes
0answers
52 views

Detecting a significant change in the difference between two rates from T1 to T2

I asked this previously but I failed to activate my account so I was not able to respond to comments and my question was never answered. Here is attempt 2: I have two rates of compliance for two ...
0
votes
0answers
18 views

are the percentage differences significantly different from oneanother?

morning, say i have 5 wheat varieties undergoing 2 treatment. when counting the seeds of the replicates the percentage difference between the means of the 2 treatments is 10% for variety 1, 30% for 2, ...
1
vote
0answers
19 views

Comparing transaction counts between samples

I have a treatment group and two control groups for customers and the count of their transactions: ...