count data

I'm wondering how I might best test for over-dispersion of raw count data over time. I have just started a project and am exploring my data, so I do not have a model to test on. I have 4000 independent customers and the frequency of their purchases per day for 44 days. I must determine whether...

Hi, I have seven categories, 'monday','tuesday','wednesday'... Each category contains count data, however I have a different number of observations on each day - some days have 10 observations, some 12, some 21. I want to test to see if the day of the week has an influence on the count and...

Hi! We have performed an experiment to see if semi-wild pigs have any food preferences (in what type of nutrient supplement we add to the food). Different foods were added in their home range at each their place. After each trial we counted the number of food pellets that were eaten. So...at...

I am looking to examine whether one variable (counts of social interactions) is associated with another variable (counts of running activity). Both variables are simply frequency counts of behaviours which were counted at the same time during 40 hour-long observation periods across two weeks...

Hello dear forum members, Using county-level panel data (N = 2500+, T = 3) I aim to examine the associations between multiple biological, socioeconomic, and psychological factors and cancer incidence. There are two outcome measures available for me: (1) cancer incidence rate, IR = (New cancers...

Hi, I have a dataset spanning two years which consists of individuals entering some process. Once they have entered this process I want to predict the number of days they will remain in this process based on some set of covariates. There are some charateristics of the data which lead me to...

Hi everyone. I'm writing up a report for my advisor, which compares count data for three conditions, across two different groups. I therefore have a 2x3 contingency table I've analysed with Chi Squared, and am using standardised residuals as a post-hoc test. However, my advisor and are...

Hi, I need some help to determine my approach. For a school project I would like to examine the effect of a policy change in the Danish registration law for certain cars, happening in june 2007. I have a dataset with the number of registrations pr. month from jan-97 to dec-15. If I put...

Basically I'm doing a recall experiment where participants are separated into 2 groups and asked to visualize the words in a specific context depending on the group. I am measuring how each independent variable does in recall (not interested in the interactin of the IVs with each other). Which...

Trying to figure out how best to carry out this analysis... So essentially I have four different species of Deer mice, infected with a high, medium, or low dose of parasite eggs. After euthanasia, I recovered larvae from different tissues of each mouse to compare differences in numbers recovered...

I'm an MSc student and not particularly statically minded and I would really appreciate some help on going about analysing count data! Please try to keep is simple! I have two species, the common frog and marsh frog and I have count data on both species since 1980. The marsh frog is...

Hello dear forum members, My study aims to address the question about physician ratings: Do they have an impact on the business value (as proxied with new patient referrals)? The sample is a panel of of U.S. oncologists (N=1,694) observed from 2009 to 2013. The outcome is a count, so for the...

Hello, I was wondering if anyone could shed some light on how to interrogate count data whichholds a lot of 0'sand therefore not normally distributed. I have pasted in an example of the dataset i'm using. It gives 4 species counts across 27 sites (replicates) across intermittent years...

Hello everyone. New member, hoping I will be able to contribute and help out! I have been working on this for about 5 days, and gotten to the point where my brain is going in circles. Hopefully you can help me understand what type of analysis this requires. I am conducting what should be...

Hi, I'm trying to analyse an experiment with this setup: A plant species with 16 different cultivars of 4-5 plants per cultivar (completely randomised within greenhouse, no blocks) An insect species that was allowed to spread freely for 4 days on the plants. The insect number per plant was...

Hi, I would like to ask what is the proper correlation coefficient to use for count data and for zero inflated count data. would Kendall tau do the job or would the data violate some assumptions of it?

Hello everyone, I'm analyzing count data in stata using negative binomial regression because of overdispersion. I'm reporting incident rate ratios using the model I've described below. Is there also a way to calculate an absolute rate reduction based on the level of exposure? This study is...

Hello. I have population data for 5 years for several species of birds and I would like to know whether the populations are growing, staying stable, or decreasing. I am using R. So far, what I have been doing is creating a linear model of the count data (or log of the count data) by year...

Hi, My data consists of occurrences of words in time windows. E.g.: Day; Word; Frequency 1; "dog"; 45 1; "cat"; 2 ... 2; "dog"; 90 2; "cat"; 4 ... I would like to estimate the ratio of day-to-day difference (i.e. for dog: 90-45/45 = 100%). For cat the increase is also 100%, but due to...

I am analyzing bird count data from surveys conducted each week (from Nov-April, when bird foraging most active near breeding cycle) for 6 years in 9 large experimental plots that are split amongst 3 regions in the landscape (6 yrs x 3 regions x 3 plots/region). We are interested in comparing...