similar to: COX PH models for event histories?

Dear All, I have a problem in understanding how the interactions of 2 ways ANOVA work, because I get conflicting results from a t-test and an anova. For most of you my problem is very simple I am sure. I need an help with an example, looking at one table I am analyzing. The table is in attachment and can be imported in R by means of this command: scrd<-

Dear all, how can I perform a post hoc analysis for ANOVA with repeated measures (in presence of a balanced design)? I am not able to find a good example over internet in R...is there among you someone so kind to give me an hint with a R example please? For example, the aov result of my analysis says that there is a statistical difference between stimuli (there are 7 different stimuli). ...I

Dear List, This is my first post, and I'm a relatively new R user trying to work out a mixed effects model using lme() with random effects, and a correlation structure, and have looked over the archives, & R help on lme, corClasses, & etc extensively for clues. My programming experience is minimal (1 semester of C). My mentor, who has much more programming experience, but a comparable

Hello, I am trying to test some results I have for significance. It has been recommended that I use R and I am completely new to this. Set-up: Groups: two groups of 8 subjects (16 total) Two conditions: alert and passive Measurements: responses for three different stimuli (A, B, and C) measured in each condition Experiment: Testing the order of conditions Group one: Alert A, B

Dear R Help, I have a general question - I know this is the R list, but I hope someone can help me out a little as I've always found the help here to be absolutely fantastic. I have run a psychological study where participants are given multiple stimuli and their responses to those stimuli are measured on the same numerical scale, i.e., the data is something like Participant Stimulus

Dear All, Apologies for sending this email to both list, but at this point I'm not sure which one could help me the most. I have 4 sets of data, 1 test and 3 different sets of controls. The measurements are binary, with a matrix of 0 and 1 I'm measuring across time (rows, ~815) the behaviour of organelles in the cell by microscopy in response to different stimuli (several measurements

I am trying to import a series of text files generated by stimulus presentation software. The problem that I am having is that the number of rows I need to skip is not fixed (depending on subject's pretest behavior) nor is the first row of the data I want always the same (the stimuli were presented in random order). So I need to bring in the .txt file (using readLines?), look for the row

Dear list members, I want to perform in R the analysis "simultaneous confidence interval for multiple proportions", as illustrated in the article of Agresti et al. (2008) "Simultaneous confidence intervals for comparing binomial parameter", Biometrics 64, 1270-1275. If I am not wrong the R function implementing the Agresti et al. method is prop.test(). I ask an help because I

Dear all! Although the Psycho-Toolbox for Matlab is free software, Matlab isn't. I'm planning to do an experiment where it's essentail to travel to the subjects, not let the subjects come to where the Matlab licences are :-( So I need to use a free software for my experiment if I don't want to by an extra Matlab licence (which I don't want to). Did anyone ever try to do

Dear all, I have tried to use R for the repeated measures experiment design in a phonetic study, and in the resulting forms I met some problems which perturb the final interpretation of the results. I will explain the experiment design first: the same 7 subjects were answering a question about 25 linguistic stimuli; the stimuli were the same utterances which were processed in 3 different ways (3

Dear all, I need an help because I don´t know how to perform the analysis in the right way, as I get different beheaviors using t-test and two ways ANOVA. In what follow I post the table, my goal and the strange results I got. I kindly ask you an help because I really don´t know how to solve this problem. So the table is this: number stimulus condition response 1

Dear list member, I deperately need an help in performing a MANOVA in R, but I encountered some problems both in the design and in the synthax with R. I conducted a listening experiment in which 16 participants had to rate the audio stimuli along 5 scales representing an emotion (sad, tender, neutral, happy and aggressive). Each audio stimulus was synthesized in order to represent a

Dear all, I am having quite a hard time in trying to figure out how to correctly spell out a model in R (a repeated-measures anova with a within-subject covariate, I guess). Even though I have read in the posting guide that statistical advice may or may not get an answer on this list, I decided to try it anyway, hoping not to incur in somebody's ire for misusing the tool. For the sake of

mgcv: Constructing probabilities for binomial GAM with crossed random intercepts and factor by variable Hello, (I'm sorry if this has been discussed elsewhere; I may not have been looking in the right places.) I ran a binomial GAM in which "Correct" is modelled in terms of the participant's age and the modality in which the stimulus is presented (written vs spoken).

Hello everyone, this is my first post here and I hope I signed up correctly and someone will take me by the hand and help me out. I am new to R and cannot figure out what to do here... ... I want to have an User Interface that requests input. I want to save this input to a variable to use it later on. I was able to do this with a modalDiaglog (

I'm relatively new to R and I'm stuck. I'm trying to construct a surface to optimize from a multivariate dataset. The dataset contains the response of a system to various stimuli. I am trying to optimize the mix of stimuli to maximize the response. To do so, I've interpolated the various datasets of type response vs. stimuli and I now have an array of functions

Dear all, I would like to know which is the right way to check the normality assumption for performing ANOVA. How do you check normality for the following example? I did an experiment where people had to evaluate on a 7 point scale, the degree of realism of some stimuli presented in 2 conditions. The problem is that if I check normality with the Shapiro test I get that the data are not

This is to announce a new package MLCM on CRAN. The package provides functions for estimating perceptual scales by maximum likelihood from data collected in a conjoint measurement experiment. Data for conjoint measurement are typically collected using a psychophysical procedure. The stimuli vary along 2 or more dimensions. The observer views pairs of stimuli and judges which stimulus of each pair

This is to announce a new package MLCM on CRAN. The package provides functions for estimating perceptual scales by maximum likelihood from data collected in a conjoint measurement experiment. Data for conjoint measurement are typically collected using a psychophysical procedure. The stimuli vary along 2 or more dimensions. The observer views pairs of stimuli and judges which stimulus of each pair

Dear all, I have 3 models (from simple to complex) and I want to compare them in order to see if they fit equally well or not. From the R prompt I am not able to see where I can get this information. Let´s do an example: fit1<- lm(response ~ stimulus + condition + stimulus:condition, data=scrd) #EQUIVALE A lm(response ~ stimulus*condition, data=scrd) fit2<- lm(response ~ stimulus +