non-parameteric

I'm trying to determine if there is a significant difference in specific-leaf area values based on two categorical soil type values. Here are what two of my distributions look like: I'm thinking of using the Mann-Whitney test but I have also read it is not the best for differently shaped...

Hello, I am a college student currently finishing up my Master’s degree in Applied Geography. I am working on a research project/thesis. The project is focused on Crime Prevention Through Environmental Design, AKA CPTED. CPTED is a theory that certain characteristics of the built environment...

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 associated non-symmetric errors according to some acceptable precept so as to determine the value of a and its...

Greetings Is it possible to compare the p-values derived from non-parametric tests to parametric tests? For example, lets say dataset 1: Copper concentration in spoil is not normally distributed, so I have to use a non-parametric test on it and get a p-value. Dataset 2: copper concentration...

Greetings I wish to be able to use post hoc analysis on my non-parametric analysis on my data. I am currently using Krustal Wallis (as I have 5 sets of data that I wish to compare). As this will only give me a p-value and a z-value which informs me if the data is significantly different or...

Hello, I analyzed some physiologic data (blood electrolyte levels etc) which was fairly skewed, so I used Kruskal-Wallis to test for differences between groups. I originally plotted the mean and SD, but I learned that plotting the median is more suitable with skewed data. My question is...

Hi, After racking my brain not knowing what to do with my data I thought I'd give it a shot and post here, as I'm still unsure what I can do to test it. Movement count per 10 seconds and survival was measured in the same animals along entire lifespan at set time points, such that when...

Okay so, I'm currently writing up my thesis, and I've got 2 between group variables and 3 within-group variables. I'm not doing a mixed design ANOVA because my data is non-normal (I'm all okay with doing non-parametric). What my main question is, is whether it is okay to run say a...

Hello everyone So glad I've found this site and hope that someone will be able to point in the right direction! I am looking at how physical activity scores (mins per week) in children, change pre and post intervention - as part of this I want to see what the affect of parental involvement...

Hi there, thanks in advance for any help you can give. I need to perform a correlation test between a parametric data set and a non-parametric data set: should I use a parametric test (Pearson) or a non-parametric test (Spearman's rho)? I'll be performing the analysis on SPSS.

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Hello, I am conducting trend analysis on rainfall time series using the Mann-Kendall rank correlation coefficient (tau). I would like to also use another non-parametric test to increase the reliability of the results, but I am having trouble finding a suitable test. I don't have a dataset...

Hi I am trying to find the non-parametric equivalent of a two-way ANOVA (3x4 design) which is capable of including interactions. From my reading in Zar 1984 "Biostatistical analysis" this is possible using a method put forth in Scheirer, Ray, and Hare (1976), however, according to other posts...

hi everyone, I want to do a statistical test for significance, but I'm having difficulty deciding which test is most suitable. I was hoping to get some help. My data: I have changes in gene expression after a pertubation, to be precise, a log2-fold change i.e. log2((expression after...

Hello everyone, Context: I'm am working on a tool that validates predicted genes. At the moment I want to validate the length of the predicted genes with the following approach: for a certain predicted gene I search for similar genes (similar above a certain threshold) in public databases (I...

Hi I had a 6 dimensional (non parametric independent variables) data set, each case representing day of my study period. I performed clustering analysis and categorized the days into four groups. Now I am looking for a statistical test which can establish whether the 4 clusters are...