How to compare paired, non-normal and GROUPED data?
Hi, community, I'm trying to solve this issue using free software on Mac OS X and Ubuntu, namely PSPP (SPSS-compatible), Gnumeric, LibreOffice, SOFA statistics, and of course, R, although I would like...
View ArticleWhich test to use?
Hi everyone, I'm working on analyzing some data right now but I'm not sure if I'm even approaching this correctly. I have a master set of data that I have broken down into individual sets. Each of...
View Articlewhich testing should i do?
I have counted bees on four different types of field margins, i have three locations where the field margins where grouped together. What i now actually have are proportions of bees for the different...
View Articlewhat kind of test?
Hi all, I really need help because I do not know which statistical analysis to perform in the following case. I the following study I tried to show that the number of missed pneumothoraces using chest...
View ArticleSample size when comparing 3 groups (proportions)
Problem: I use a common clinical specimen divided equally into two sets with each set to test 3 culture media for growth of a certain organism after processing. The 1st is processed by method A. The...
View ArticleGene expression analysis - FDR and p-values
Hi, I'm using Affymetrix microarrays to check if there exist some differences in the gene expression of two group of animals that have been differently treated. I'm using a t-test with permutations (as...
View ArticleFixed effects vs. Random Effects
Hi we had 5 investigators 1)hand out 100 surveys and 2)record a certain feature of each of the 100 subjects. That feature that they recorded is the outcome and may be subject to the differing biases of...
View ArticleNon-parametric alternative to repeated-measures ANOVA with a between-subjects...
Hello, I'm trying to do a repeated-measures ANOVA but my data is likely violating the multivariate normality assumption. My question is: Does water contamination differ by year when comparing one group...
View ArticleWhich test should I use to compare these two groups?
Hi everybody. I have two groups of doctors, group A and group B. I'm trying to see if there is any statistical difference between them in their ability to correctly diagnose a certain condition. Group...
View ArticleHelp to determine the correct statistical method (non-parametric MANOVA?)
I can perform very basic statistics, but I have a serious problem with figuring out what to use in this case. I'm using R (within R Studio) since it is the only statistical program available to me, but...
View ArticleComparing two methods to measure disease severity
I am testing a new, fast method to score disease severity in an animal model of a human disease. M appears to be less sensitive than the gold standard scoring method, G. G is discrete and has a range...
View ArticlePseudo-time lapse experiment: repeated measures ANOVA??
I am measuring disease severity, using 5 different types of measurements, in animals treated with drug X, over multiple timepoints. The measurements can only be made when the animal is dissected. We...
View ArticleConfidence Level for device tests in fda
Hello, I want to know what confidence level is required to be considered for proving a medicine or device is good and it will be great if anyone can provide a document for it and also for design of...
View ArticleSample size calculations for a study
Hello I need some advice regarding sample size calculations. I need to calculate a sample size for a study testing a new drug. In the study there will be 4 groups: 2 groups of the drug with different...
View ArticleWich method to use
Hello, I am doing research but cannot figure out which statistic method to use. Please help me because I am not sure of what to do exactly. My researchhypothesis is that you are able to derive the age...
View Articlecomparing change from baseline (two treatment groups, binomial data)
I am comparing the effectiveness of a vaccine in reducing the prevalence of the targeted protein. I have baseline data (before the vaccine was even available), and now have data from vaccinated and...
View Articleneed help regarding statistical methods for a project :(
hi all, i have been tasked to do a biostats project and really need some advice from all the great biostatisticians out there! i have two different treatment outcomes (Yes or No), and a whole bunch of...
View Articlecomparing two dependent survival curves
Is it possible to compare two survival curves using the same outcome data but two different exposure data in all subjects? I have a dataset with survival of patients and I want to know which of two...
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Normal distribution
Hi, I am working with a microarray dataset. The database contain values on 208 probes for 58 subjects. The readouts for each probe is an arbitrary unit from 0 to 5000, according to the intensity of...
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