Questions tagged [anova]

ANOVA stands for ANalysis Of VAriance, a statistical model and set of procedures for comparing multiple group means. The independent variables in an ANOVA model are categorical, but an ANOVA table can be used to test continuous variables as well.

Filter by
Sorted by
Tagged with
0
votes
0answers
12 views

How to find a virulence factor?

I have a big data set of protein expression. I just put the head of it. ...
0
votes
0answers
9 views

Which is the best way to run a two way repeated measures anova in R

I have run a repeated measures anova with two IVs (score 1-7) and a DV (score 1-7). These are my options so far: aov(dv ~ iv1*iv2 + Error(id/(iv1*iv2)),data = df) ...
0
votes
0answers
6 views

How do I add an interaction term to MANOVA in R?

I would like to compute Pillai's Trace from multivariate analyses in R on an interaction term. A subset of my data is: ...
0
votes
0answers
5 views

numerical response variable and categorical explanatory variable How to transform the response data to normal distributed [closed]

I wish to use normal distributed data to do the ANOVA test but it is not very common to transform response variable directly and it doesn't make sense to transform the categorical variable as well. ...
0
votes
0answers
5 views

What is the correct way to specify error terms and fixed effects vs random effects in an anova in R?

I am very new to coding and stats in general, so please let me know if I am making any big mistakes here. I am writing code to analyze the following data: ...
0
votes
0answers
7 views

Not sure how to start analyzing my dataset- could use any wisdom

I am new to statistics, and while I am not asking for anyone to do anything for me, I would appreciate and use any statistics wisdom that I could get. I was entrusted with some undergraduate research ...
0
votes
0answers
3 views

How to perform a 3-way MANOVA correctly in R?

An experiment evaluated 3 factors and 3 responses to treatments. The selected factors were the chemical used (Chemical), the mixing speed (...
0
votes
1answer
6 views

In the R package spANOVA can coordinates be entered directly as Lat/Longs or is a map projection required?

I have some data on fish abundance in a harbour in Canada that I'm analyzing using the R package spANOVA (Spatial ANOVA). I'm using the function aovSAR.gen which takes the arguments: aovSar.gen(...
1
vote
0answers
10 views

What type of analysis to do for Dissertation- EMOTION RECOGNITION

In my study, participants take part in the State Trait Anxiety Inventory (STAI) where they are ranked into high or low trait anxiety groups. Participants are then shown multiple videos of 7 different ...
0
votes
0answers
8 views

ANOVA, does “equal population variances” mean the same as “a single population”?

In ANOVA the assumption is made that the population variances of the different groups are the same. Assuming $H_0$ is correct, all population means are also the same. In this case, would it not be ...
0
votes
0answers
14 views

Should I use a parametric test or non-parametric test?

I'm analysing a set of data on the fluorescence intensity of a particular receptor. All the data are in the form of a fraction as they are being compared to a control. ie. fraction = intensity of test ...
0
votes
0answers
5 views

Comparing mixed effect models using deviance statistics - comparing model 1 vs. 4 instead of 1 vs. 2, 2 vs. 3, etc

I am relatively inexperienced with mixed effect models and trying to build a model to fit my outcome of interest. I have read and followed along with chapter 4 of Singer & Willet (2003), as well ...
0
votes
0answers
8 views

Log-transformed data P-value interpretation?

I have logged transformed some data to correct the normality assumption. I then conducted an anova using the logged data to test for differences between group means. (in R) Can I still use the P-...
0
votes
0answers
6 views

Confidence interval calculations Tukeys vs Bonferroni vs Fishers LSD?

I am trying to work out how the Confidence interval calculations for the Tukey, Bonferroni and Fishers LSD differ and/or are similar from each other? From my understanding they all consider the ...
0
votes
0answers
8 views

Find significance in pairwise comparisons when not explicetedly reported

I am interested in the reported statistics in the paper https://www.tandfonline.com/doi/full/10.1080/09602011.2020.1715231. To my understanding, they do not report explicit pairwise comparisons, see ...
0
votes
0answers
11 views

Differences between pairs of mean. SED and LSD confidence intervals

I have a Anova related question and would really appreciate some help. I am trying to creat a table with: The estimate differences between means, Standard error of the differences (SED), and the 95% ...
0
votes
0answers
11 views

Why should the difference between the adjusted R-square and predicted R-squared be less than 0.2? [closed]

I am building a regression model using RSM-CCD method in Design-Expert software. All the statistical parameters are OK. The difference between the adjusted R-square and predicted R-squared is less ...
1
vote
0answers
10 views

How to account for mediators in ANOVA?

So I have two IVs (customization, purchase type), three mediators (self-expressiveness, social connections, evoked comparisons) and one DV (happiness). Purchase type is either experiential or material,...
0
votes
1answer
22 views

what type of data analysis should I carry out

In my experiment I have two groups each with 30 participants (experimental group and a control group) The experimental group consists of autistic individuals and the control consists of neurotypical ...
0
votes
0answers
27 views

How to analyzed results from several independent replicated experiments

I am not very good in biostatistics and I have a question. I investigate the result of knockout of a particular gene on the disease severity. I take WT or KO mice, induce disease, and record readings. ...
1
vote
0answers
18 views

Setup and analysis of deterministic simulation (Design of experiments, ANOVA)

My problem is as follows: I have a time series simulation (implemented in Python), which is roughly about an abstract modeled storage object digesting and creating energy flows. These (resulting) ...
1
vote
0answers
24 views

How to compute % contribution to total variance

I would like to determine the percentage of variance each group contributes to an observed total variance. I would like to know the simplest way to calculate this, and to gain some intuition as to ...
2
votes
1answer
105 views

What is more powerful – an ANOVA test or post hoc tests?

From answers on this site I have learned that it is possible to get significant results from multiple comparison tests ("post hoc"), even if ANOVA did not yield a significant result. I ...
0
votes
0answers
17 views

statistical test to identify the best group of values [closed]

I have very little to no knowledge of stats and hope that you could help me with the problem I am encountering. In brief: I have 5 sets of measurments for different concentration of compounds, using ...
0
votes
0answers
8 views

Test session and test x group interactions

I am currently doing a lit review as a bachelor thesis and I am struggling with one aspect of the statistics in one article. The article is comparing two treatments with pre-treatment values and post-...
0
votes
0answers
9 views

Investigating effect of group on difference scores in mixed ANOVA

I was wondering what is the most elegant way to investigate group differences in change scores? Here's what I'm trying to do. Imagine there are three groups (a,b,c) where each participant is measured ...
0
votes
1answer
26 views

Main effect vs simple effect

In the following linear model: $y = \beta_0 +\beta_1 x_1 +\beta_2 x_2 + \beta_3x_1x_2 + \epsilon$ what are called $x_i$? The term $x_1x_2$ is the interaction. In ANOVA, $x_i$ are named "main ...
0
votes
0answers
16 views

Interpreting the normal plots (regarding alpha) from fullnormal(), halfnorm(), qqPlot()

Consider a single replicate of the $2^4$ factorial design (Data source: [Example 6.6] Montgomery, D. C. (2019). Design and analysis of experiments. John wiley & sons.), and use a normal ...
0
votes
0answers
8 views

Why do repeated measures Anova tests and 2-sample dependent t-tests provide the same inference in a case with two treatments?

Why do repeated measures Anova tests and 2-sample dependent t-tests provide the same inference in a case with two treatments? they are different tests but for a case of two treatments somehow they are ...
0
votes
0answers
9 views

Which comparison between models through ANOVA should I use?

I have 3 factors (A, B and C) in which each factor has two levels, a response variable (Y) and random effect (R). I have a model of the form: ...
0
votes
0answers
5 views

How to interpret SD from output of anovaVCA model?

I'm using "VCAdata1" data from VCA Library containing device measurements from 3 devices on each day (1-21) and on each lot (1-3) and subsetting the data to include only sample=5 . So for ...
0
votes
0answers
7 views

Should I use Friedman's test in this case?

I'm trying to find out if certain factors matters more to people than other factors. I have five different factors and on a 5 point-likert scale, I have questions about which factor is more important ...
0
votes
0answers
8 views

Non-parametric equivalent to ANCOVA

I would like to do analysis with co-variate. However, some of my data is skewed and has outliers, so I would like to use non-parametric approach. The issue is that, I could not find any non-parametric ...
0
votes
0answers
19 views

Biological vs Technical replicates in cell culture experiment - how to adjust mixed model

I am new to statistical analysis for lab-based research and I want to understand how the following two scenarios differ in how you would specify a mixed model: Tumour sample from 10 patients. Each ...
1
vote
0answers
6 views

BAckground Anova vs Individual Protein ANOVA

In proteomics often two conditions are compared (let's say control vs treatment) and the abundance of thousands of proteins (let's say 20.000) is measured. To determine which proteins are ...
0
votes
0answers
29 views

Which statistical tests do I use for two categorical variables with more than two subgroups?

I have two variables. The first (will call it X) is X=(morning, afternoon, evening, night). So, 4 categorical times of day. The other (called Y) is another categorical variable, i.e., Y=(cat 1, cat 2, ...
0
votes
1answer
16 views

Significant difference/ANOVA test when some values occure only once

I have fake dataframe with neighbrhood codes and prices of houses in those neighbrhoods, with this amount of values for each negihborhood: ...
2
votes
1answer
48 views

How to calculate “by hand” between group variance and the ICC for a three-level hierarchical model?

Introduction: This question is related to this and this questions that were answered before, but I would like a more detailed answer on how between-groups variance are calculated in a (null) three-...
0
votes
0answers
14 views

Mixed Repeated Measures ANOVA vs. multilevel random effects model

I have a dataset that contains survey responses from participants attending a training workshop. Surveys were administered prior to training, just after training, and 3 months post training. Moreover, ...
0
votes
0answers
6 views

How to look covariate for treatment between patients and controls?

I have this study where we have 2 patient groups, both on a the same medication (for ethical reasons, patients had to remain on their medication), and 1 control group. There are significant ...
0
votes
1answer
24 views

summary(), anova() type 3, Anova() type 3 not producing similar results for lmer model

First off, I have read a plethora of answers on this site but can't seem to find something that satisfies my situation below: ...
0
votes
0answers
8 views

Is a “deviance table” equivalent to the type 2 or type 3 ANOVA?

I was taught, that ANOVA assesses the main effects and interaction effects of a linear model. In other words, it jointly tests appropriate model (with categorical IVs) parameters, telling us, if all ...
6
votes
6answers
145 views

Comparing two, or more, independent paired t-tests

Can we compare the results from two, or more, independent paired t-tests? For example: I want to test if drug 1 and drug 2 are effective to reduce weight. I have a control group (that will consume a ...
0
votes
0answers
15 views

rm MANCOVA's univariate result does not match the post hoc results. Strange!

I have run a repeated-measures MANCOVA with 2 dependent variables and a 5-level repeated-measures intervention. The multivariate effect of intervention is significant. The univariate effect of ...
2
votes
1answer
32 views

Transforming two-way ANOVA into one-way ANOVA by ignoring one factor

I'm building up a sample to test if the water consumption (for example) changes among two smart technologies water-machines (A and B), and I'm adding another group C for control (standard machine). I ...
0
votes
0answers
8 views

Power analysis for anova when one set of comparisons is particularly of interest

I've been messing around with how to perform a power analysis for an experiment with three groups: control, disease model, and disease model + treatment. From past studies I have a good estimate of ...
1
vote
2answers
19 views

Comparing 2 models with anova in R?

I'm struggling to interpret this outcome. I have 2 models Model_1 <- lm(formula = gamble ~ income * gender) Model_2 <- lm(formula = gamble ~ income + gender) ...
1
vote
0answers
20 views

One-way ANOVA and Two-way ANOVA p-value

I have a dataset with 270 observations, 90 for each group (A,B,C). With One-way ANOVA I'm testing if there is a difference in my variable y depending on each one of the groups A,B and C. ...
0
votes
0answers
16 views

Mixed ANCOVA: What to interprete?

I've used several statistics packages to run a mixed ANCOVA with one within-subjects factor, one between-subjects factor and one covariate and I am confused as the output produced varies. When I run ...
0
votes
0answers
5 views

3-way mixed ANOVA with a covariate - how does SPSS adjust for the covariate?

I'm trying to run a 3-way mixed ANOVA (3x5x2, where the 2 is the between-factor) in SPSS. My dependent variable is accuracy, and thus cannot exceed 1. However, when I enter the covariate measures as ...

1
2 3 4 5
91