0
votes
1answer
35 views

How to correct the degrees of freedom?

I'm running mixed design ANOVA using R. Somehow, I got incorrect values for the degrees of freedom (Df). There are two factors: temperature (2 levels) and ...
0
votes
1answer
40 views

Two-way repeated measures ANOVA with unbalanced data

I have a system / operator repeated measures data set for which I would like to answer the questions: is system 1 quicker than system 2 is operator 1 quicker than operator 2 does the order of using ...
1
vote
1answer
53 views

How do I perform this complicated ANOVA type analysis in R?

I have the following type of dataset: | | | variable_r | subject | gender | age_group | Cond_1 | Cond_2 | ...
3
votes
1answer
35 views

Beginning anova in R: Phantom significance when testing for interaction terms

Suppose I create a dummy scenario as such: > A <- rnorm(10000) > B <- rnorm(10000) > C <- rnorm(10000) > Y <- A*B + rnorm(10000,sd=0.1) ...
1
vote
0answers
34 views

Repeated measure two-way ANOVA (non-parametric)

Non-parametric ANOVA – a hot topic that is unanswered. There are many questions on this topic online. However, they all seem to end in a debate and no definite answer or clear explanation (that I ...
0
votes
0answers
36 views

ANOVA to find subjects that responded significantly different between treatments

I have a dataset composed of several subjects exposed to two different treatments (treat) in three distinct times (test), and I am interested in highlighting which subjects have significantly ...
0
votes
0answers
27 views

Understanding ANOVA formula in R and choosing the most appropriate model

I am new to R (and by extension statistics), and am having a tough time in making sense of this repeated measures ANOVA formula, please bear with me. I think I understand what the formula implies, but ...
1
vote
0answers
26 views

Partition of sums of squares (ANOVA)

Can anyone explain the theory (or the formula) about computing Sum Sq (bold highligh below) related to regression items? The Wikipedia link gives an introduction on how to calculate the total, model, ...
2
votes
0answers
60 views

In R, what does anova(f1, f2, f3) compare?

I'm trying to understand the reason why anova(f1, f2, f3) and anova(f1, f2) gives me different result while anova(f1, f2, f3) and anova(f2, f3) gives me the same. Here's the code: ...
1
vote
1answer
60 views

Why do ANOVA p and F values change?

I am currently conducting a two-way ANOVA on a dataset and have noticed how significance and F values change dependent on the type of ANOVA I use in R. Why is this? For instance, if I run a two-way ...
2
votes
0answers
46 views

How can I make 2-way ANOVA (Type I, II and III) with R?

I have the following data with factor 1 (A, B and C) and factor 2 (D and E): $$ \begin{array}{ccc} \hline & D & E\\ \hline A & 68 & 59\\ & 65 & 57\\ & 63 & 54\\ ...
0
votes
0answers
31 views

Analysis of repeated treatment design (Linear panel model vs. ANOVA)

General information Assume you have the following quasi-experimental repeated treatment design (T = Treatment, M = Measurement): ...
0
votes
1answer
45 views

ANOVA and finding differences between multiple groups over time

I was given a dataset to analyze with two factors, time and treatment, and one continuous dependent variable. Since the same individuals were measured at multiple times, technically it probably could ...
0
votes
0answers
13 views

ANOVA - comparing rows with replicates

I have a situation where I want to test for differences between rows and columns in my data frame: ...
0
votes
1answer
19 views

question on plotting error values for treatment effects from multiple regression output

Say I have some data, where a dependent variable, dv, is a function of some independent variable, iv, and a categorical ...
1
vote
1answer
52 views

Interpreting the ANOVA output for hierarchical linear regression

I followed this tutorial to learn Hierarchical Linear Regression (HLR) in R, but couldn't understand how to interpret its sample output of ...
1
vote
0answers
50 views

Using repeated measures anova: Am I right?

We have just finished an experiment, where we had samples distributed into 6 groups and each group receiving a different treatment. Each group had 5 samples, with 20 replicate measurements taken per ...
2
votes
1answer
28 views

R multcomp: contrasts for Tukey

I want to use the glht() function from package multcomp. In the linfct argument, I provide ...
1
vote
1answer
64 views

2x2 ANOVA, no main/interaction effects, post-hoc cell mean comparisons necessary/allowed?

I have a 2x2 between-subject design with unequal cell sizes. I ran an ANOVA with type I sums of squares to account for the unequal cell sizes. Neither of the two main effects nor the interaction ...
2
votes
0answers
36 views

Compare rows across columns - classic ANOVA?

I have a situation where I want to test for differences between rows and columns in my data frame: ...
1
vote
0answers
33 views

What is the equivalent of a repeated ANOVA using a mixed effect model with lme?

I have a data frame with this structure: ...
0
votes
0answers
24 views

Perform analysis of deviance on R/RPy aov() models

I am using stats.aov() in R to perform an ANOVA on my 2x2 within subject exeriment design. I am unsure how best to model the data so I have formulated 3 models, ...
1
vote
1answer
56 views

Two Way ANOVA repeated measurement

I am trying to compare the three replicate samples taken at different time point to see if the replicate one differ from replicate two and three and visa verse. My interest is to see if the three ...
0
votes
1answer
28 views

Repeated measures design with measurements from different groups of animals

In a repeated measured design we measure a particular variable at different time points from the same subjects. In animal experiments, if animals are sacrificed at every time point to measure a ...
0
votes
1answer
65 views

ANOVA and post-hoc analysis using R when we only have means and SD of three populations

I want to perform an ANOVA using R. I have three populations, represented by their respective means and SD: Pop.1: 5.5 +- 0.4 (n=100) Pop.2: 5.9 +- 0.3 (n=150) Pop.3: 6.2 +- 0.5 (n=200) Which is the ...
1
vote
1answer
107 views

anova type III test GLMER wiht R

I am fitting a GLMER with lmer R package. I'm looking for an anova table with p-value shown therein, but I cannot find any package that fits it. Is it possible to do it in R? The model I am fitting ...
1
vote
0answers
39 views

Reporting two-way ANOVA

I've been trying to figure out how to properly report a two way ANOVA with two between-subject variables and their interaction. Most references I found suggest to report it in the following way: ...
0
votes
0answers
25 views

One Factor Repeated Measure, Two Way ANOVA

Is there some way in R to output not only the main effects and the interactions of the two factors using an aov() like function but also the variance of the subject within a non-repeated factor? For ...
1
vote
0answers
64 views

R - Post hoc comparisons in 2x2 ANOVA unequal sample sizes

I have a 2x2 between-subject design with (slightly) unequal cell sizes. Hence I chose to use the anova(lm(...)) function so that Type 1 SS are used: ...
0
votes
1answer
77 views

Why must one use ANOVA to interpret the impact of interaction effects and factor variables? [closed]

What is the purpose of the ANOVA table? I once learned that you can only interpret the significance (p-value) of a multi-level discrete variable, or an interaction effect using the ANOVA table. Why? ...
0
votes
0answers
16 views

Comparing F-values of covariates in R

I'm new here and have a question regarding ANOVA in R. I have an ANOVA table like this from running anova(model) in R, where ...
0
votes
0answers
232 views

One-way ANOVA with unequal sample sizes

I have a function for performing one-way ANOVA in R: ...
0
votes
1answer
32 views

Determine which group is more important

I have a question how to analyze mean differences where I am unsure whether I am lacking the statistical vocabulary or simply ignoring something important. I have a 5 point satisfaction variable ...
1
vote
0answers
138 views

ANOVA on percentages

Please read edit 3 first I am trying to find out the significant factors in a dataset of percentages, a sample of which are below. The difficulty is that the data violates the assumptions of ANOVA, ...
1
vote
2answers
120 views

inter vs intra group variance

Consider this example: ...
1
vote
0answers
59 views

lme vs lmer vs aov for three factor repeated measures design

I'm trying to run a tree-way repeated measures ANOVA on the following data: I have a completely balanced design with three within-subject factors (type, form and ch - channel) and one dependent ...
0
votes
1answer
37 views

Should we conduct post-hoc tests when there is a significant interaction but no significant main effects?

I have data showing outcomes of some treatment on different people grouped by sex and age (grouped into: infant, child, adult). I need to investigate if there is any difference in outcome among age ...
0
votes
2answers
106 views

Analysis using ANOVA

I want to compare 6 designs of spoons (D1,D2,D3,D4,D5,D6) in 20 children (blocks).I also want to see whether holding the spoon in right or left hand affects food-pinching response(number of M&M's ...
0
votes
2answers
332 views
0
votes
0answers
35 views

Which post-hoc test should I use after finding significance in two-way within subjects ANOVA?

I have tested 3 treatment conditions on 7 scenarios where each scenario had 7 trials (each for 20 subjects). After running an ANOVA (...
0
votes
0answers
52 views

aov() error strata degrees of freedom

I have the following data frame: ...
0
votes
0answers
41 views

ANOVA or any other tests for differences in R

I have a timecourse dataset consisting of 3 groups of patients as follows: Group1: control Group2: Medication A to reduce pain after a medical procedure Group3: Medication B to reduce pain after a ...
3
votes
0answers
65 views

Tests of within subjects contrasts in R

I have run a split splot model in SPSS (via repeated measures function) and I would like to reproduce my results using R. To do so I used ezANOVA function from ez package to obtain sphericity tests ...
0
votes
0answers
106 views

One-way ANOVA from summary data in R

I want to statistically compare the mean values from eight different groups. I do not have the raw data, but have the sample size, mean and associated standard deviation and standard error. I was ...
2
votes
0answers
83 views

Nested ANOVA: Unequal sample sizes? Variance components?

I am completely out of my depth on this, and all the reading I try to do just confuses me. I'm hoping you can explain things to me in a way that makes sense. (As always seems to be the case, "It ...
1
vote
1answer
128 views

Mean ranks and standard errors of Kruskal-Wallis test

While it's easy to compute the p-value of Krsukal-Wallis non-parametric test using the kruskal.test() function, I don't know how to compute the mean ranks and ...
5
votes
1answer
119 views
0
votes
0answers
28 views

Fitting an ANOVA with too many predictors in R. No p-values but how can I still interpret the model?

So I've fit an ANOVA model to 32 predictors and 32 data points. The summary output simply gives me the SS for each predictor and no F-stat or p-value. Is there any way to still make some sort of ...
0
votes
1answer
71 views

compare models using anova in r

I got the following outcome. I am confused with the interpretation. When I consider RSS then model 2 is better than model 1. What does that high p value mean? Does in influence my conclusion?? ...
1
vote
1answer
41 views

model compare by anova test

I did model test of in anova. once mod1 vs mod2 , other mod2 vs mod1. Does it matter? CAn I compare two models of different df and different parameters? ...