similar to: anova post hoc tests

Dear all, I run a kruskal wallis test and found significant results. Then, I conducted all pairwise comparisons and found no significant results. Could anyone please give me a hint as to why this happens or redirect me towards a specific web page where I can find more info? (I used alpha=5% and made no bonferroni or other correction for the pairwise comparisons) Thank you   Dr. Iasonas

Hi all, does anyone have any practical examples of how this command can be used in prettyR? add.value.labels(x,value.labels) I mean, can we have the SPSS style of using numbers and/or labels if we want to? Thank you for your time Jason Dr. Iasonas Lamprianou Assistant Professor (Educational Research and Evaluation) Department of Education Sciences European University-Cyprus P.O. Box 22006

Dear all I have found that the two "equivalent" commands do not produce the same results. 1. (I wrote this command by hand, this is what I would do usually) >summary(aov(eduyrs ~ cntry * edf, data=ESS1)) Df Sum Sq Mean Sq F value Pr(>F) cntry 1 257 256.65 21.2251 4.243e-06 *** edf 4 11010 2752.42 227.6296 <

Doea anyone know how to compute components of variance analysis? For example, I have the score of pupils on a test. Each pupil belongs to a school and within each school I may have several classes? How can I estimate the variance of the pupils, schools, classes and the errror variance? Any examples? Any help will be appreciated. Jason Dr. Iasonas Lamprianou Department of Education The

Dear colleagues can somebody help me by showing how we can compute m-estimators in R? thanks Dr. Iasonas Lamprianou Assistant Professor (Educational Research and Evaluation) Department of Education Sciences European University-Cyprus P.O. Box 22006 1516 Nicosia Cyprus Tel.: +357-22-713178 Fax: +357-22-590539 Honorary Research Fellow Department of Education The University of Manchester

Dear colleagues, I teach statistics using SPSS. I want to use R instead. I hit on one problem and I need some quick advice. When I want to work with ordinal variables, in SPSS I can compute the median or create a barchart or compute a spearman correlation with no problems. In R, if I "read" the ordinal variable as numeric, then I cannot do a barplot because I miss the category names. If

hi all, is there a cd-rom image with a full R pre-installation which I can give to my students so that if they want to run R on their computer, they will be able to run it from the cd-rom without having to install it on their computer. That way, they can have a 'protable' R package installation in their bags, and they can use it on any machine. Is this possible? Dr. Iasonas Lamprianou

Dear all I have a factor variable which holds values like "Engineer", "Doctor", "Teacher" etc. I would like to collapse those categories so that Teachers and Sociologists form one category named "Teach & Soc" etc. However, I do not know how I can do it. Recoding does not seem to work. Thank you Dr. Iasonas Lamprianou Assistant Professor

Dear colleagues, i am carrying out an ordinal regression model. I try it on SPSS but I "flirt" with R as well. I have a few questions. 1. What is the most reliable/tested/trusted package for ordinal regression in the R world? 2. Also, I have a statistical question. What is the danger of having to many 'empty cells' in ordinal regression? How many empty cells are too many? Do

Dear all, i have spent a lot of time trying to solve this problem, but I am sure that there must be a simple solution. So, as a last resort, I am coming back to you again. I have a dataset with some (almost random) values in many variables. Lets say that the dataset represents the scores of students to test questions. What I need to do is to sum the scores for each student. However, wherever

Dear all, I am running a logistic regression and this is the output: glm(formula = educationUniv ~ brncntr, family = binomial) Deviance Residuals: Min 1Q Median 3Q Max # ???? ????? ?? ???????? -0.8825 -0.7684 -0.7684 1.5044 1.6516 Coefficients: Estimate Std. Error z value Pr(>|z|) (Intercept) -1.06869 0.01155 -92.487 <2e-16 *** brncntrNo

Dear friends, two years ago (as I found on the web) Paul sent the following message but I was not able to find if he got an answer. Today I have the same question and it would be great if I could find out that this test has been implemented (somehow) in R. Please do not confuse it with the Brown-Forsythe test of equality of variances. Thank you: I've been searching around for a function for

Does anyone know if the lmer function of lme4 works fine for unbalanced designs? I have the examination results of 1000 pupils on three subjects, one score every term. So, I have three scores for English (one for every term), three scores for maths etc. However, not everybody was examined in maths, not everybody was examined in English etc, but everybody was in effect examined on four subjects. I

Hi I am using R version 2.4.1. How can I upgrade to version 2.5 without having to install all the packages again? Thanks Jason Dr. Iasonas Lamprianou Department of Education The University of Manchester Oxford Road, Manchester M13 9PL, UK Tel. 0044 161 275 3485 iasonas.lamprianou@manchester.ac.uk ___________________________________________________________ now. [[alternative HTML

Dear all, I am looking for ways to compute standardized logistic regression coefficients. I found papers describing at least 6 different ways to standardize logistic regression coefficients. I also found a very old (Thu May 12 21:50:36 CEST 2005) suggestion by Frank E Harrell (one of the colleagues who frequently contribute on this list) saying... Design doesn't implement those because they

Dear friends, does anyone know how I can run a zero truncated poisson regression using R (or even SPSS)?   Dr. Iasonas Lamprianou Department of Social and Political Sciences University of Cyprus [[alternative HTML version deleted]]

Dear all, I am doing a social network analysis using ergm. I import a rectangular matrix of data and then I build a network using the following command: ng <-network(mat,directed=FALSE) I then attach vertex names using commands like this: set.vertex.attribute(ng,"SchoolType",mSchType) where SchoolType can take six different/unique values. Then, I run ergm models successfully using

Dear all,  I am not sure if this is the right place to ask this question, but I will have a go. Please redirect me to a different place if this is not the right one! I have a (relatively) simple problem which causes me some frustration because I cannot find the solution. I measure ten variables (var1 to var10) every day, they are all continuous (linear) and most of them are correlated. Some days,

Hi friends, does anyone know how we can 'control' R from Visual Studio .NET? e.g. start R, send a set of commands, save the results and open the results using Visual Studio. Thanks Jason Dr. Iasonas Lamprianou Department of Education The University of Manchester Oxford Road, Manchester M13 9PL, UK Tel. 0044 161 275 3485 iasonas.lamprianou at manchester.ac.uk

Dear all (a)in SPSS PASW there is a 'split file' command is repeats the same analysis for all sub-groups. Is there a split file equivalent in R? (b) Is there a package in R that will compute immediately statistics like Hosmer and Lemeshow Test, pseudo-R squares etc without my intervention? I am mostly interested to find easy solutions for my students. They are not