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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.

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Running analyses with uneven group sizes

I was trying to run a study with 100 people per condition for 4 conditions. When I looked at the results, the group sizes were skewed - some had 80, some had 120. If I'm planning on running a series ...
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Analyzing behavioral change: Comparing 2 measured weight curves to a model curve

I'm currently in the process of analyzing experimental data and would like to hear your opinion on the method I would like to use to test my hypothesis. I had an experimental setup where I recorded ...
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6 views

Propensity Score Matching and Outcome Analysis - Variable Use

If we match treatment and non-treatment people on a variable (e.g., gender), should we use that variable in the assessment of the outcome? Let's say we match exactly on gender and approximately on IQ....
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1answer
11 views

Two-way repeated measures anova using a “categoryish” independent variable?

I am trying to run a two-way repeated measures anova in spss but i think my data needs restructuring. I have run anova's in spss before so i am familiar with process. The problem is that when i have ...
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11 views

Can I use a two way ANOVA to test temperature over time?

I have ran an experiment on a solution. Over a 2 hour period I have observed the effects of what temperature can have on a substrate but also what the effects of running the experiment over time have. ...
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1answer
27 views

Are the results of my paired tests false positive?

I am dealing with a strange situation which I hope you can come up with a solution. I have 3 pared group(n=7 for each) which I tried to see if they are significantly difference and if so, in which ...
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1answer
20 views

Reporting betareg outcome - how to compare non-nested models?

I am looking for advice how to gain and report results using beta regression for an ANCOVA-like model. My model is as follows: ...
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5 views

Temporal test for treatment when control is zero

I have a 5-year time series of abundance for three replicates in response to treatment, and three control replicates. ...
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7 views

Determine sample size for three-way ANOVA with repeated measures

My experimental Design looks something like this: two groups do a Simon task. There's four dependent measures for every subject: Reaction times to congruent vs. incongruent trials in n after a ...
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1answer
81 views

r - 2-way Repeated Measures ANOVA - different degree of freedom among ezAnova, aov and lme

I would like to run a simple repeated measures ANOVA with 2 factors (Food & Drink). Let's have a dummy df: ...
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16 views

Methods of analysing gender disparity amongst bonus awards

I've been asked to do some analysis of bonus awards made in a firm of accountants to determine whether gender is a factor, and if so, how much of a factor. The company is medium sized: about 300 ...
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16 views

Assessing Normality in ANOVA - Dependent Variables or the Studentized Residuals?

I ran an between-subjects repeated measures (2*2*2) ANOVA in SPSS using GLM. One of my dependent variables didn't meet the Test of Normality (Shapiro-Wilk p = 0.047) according to the table. The Q-Q ...
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Bacteria picked up on fingers after multiple surface contacts: non-normal data, repeated measures, crossed participants

I have two groups of participants (A=wearing gloves, B=no gloves) who are repeatedly touching contaminated surfaces with E. coli. I want to know if there's a difference between the amount of bacteria ...
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1answer
20 views

ANOVA as Multiple Linear Regression - variance due to different factors and interactions

I am doing a 2-way anova with repetitions, but the number of repetitions is not always the same. So I am using multiple linear regression with dummy variables. When testing for the interaction effect,...
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1answer
32 views

3-way ANOVA with a significant 2-way interaction. What are my next steps?

I have performed a mixed 3 way ANOVA: Group (2 levels) x Factor2 (2 levels) x Factor3 (2 levels). There was no significant 3-way interaction; however, there was a significant 2-way interaction ...
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16 views

TukeyHSD for the interaction term after mixed ANOVA

I have recently run a 2 (between variable: native, non-native) x 3 (offer: £1, £2.5, £4) mixed-design ANOVA with repeated measures on offer type. I got a significant result for offer type and the ...
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Is mixed models a better choice comparing to ANOVA? (SPSS)

I have two groups in which I compare two times (before and after treatment). At first, I tried an repeated measures ANOVA and observed significant difference between groups. However, I have the ...
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6 views

Covariates in ANOVA using SPSS [on hold]

I did a repeated measures ANOVA in SPSS. I would like to know if it is correct to place each covariate, one by one, in the field "covariables" to control possible dependent variables that change the ...
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unpaired testing of differenes between changes observed in distinct subgroups of a population

I would like to find out whether measured biological changes in a disease condition compared to a healthy control condition differ significantly between the two genders. So instead of classical ...
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9 views

Type-I error adjustment for simple effects when 2x3 factorial ANOVA interaction only is significant

I have found several questions and answers that skirt around my problem but I haven't been able to deduce a clear solution. My situation is this: I ran an experiment with a 2x3 factorial design (call ...
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11 views

Anova test with quantile regression model

I want to create a anova test with two or more non-linear quantile regression models: ...
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13 views

repeated measures ANOVA with a continuous independent variable that does not vary between subjects

I am trying to perform an ANOVA repeated measures analysis using R. For each subject I have test results at different time points. I also have the independent continuous variable "dose". However ...
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1answer
22 views

Null hypothesis of same group means

I have 4 (different sized) groups, each group having more than 20 values. Now I have made the following hypothesis: The mean between these groups is the same and I have tested it with ANOVA getting a ...
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Use a two-way repeated measures ANOVA when we have two independent groups

Our study consists of two independent groups named as EXPT and CTRL. There are 10 subjects in each group, and measurements at two points: pre and post test. Can we use a two-way repeated measures ...
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26 views

Statistical Design Assistance

I come to you all with a (hopefully) relatively simple question. Sorry for any grammar mistakes, english is not my first language. Background I am creating an experiment that is building off the ...
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1answer
20 views

Specifying contrasts using afex

I would like to understand how to specify a contrast in a follow-up analysis using the afex package. Below I included code from the documentation and explain why I ...
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1answer
39 views

How do I perform an ANCOVA ? (master thesis deadline) [closed]

My dataset consists of several morphological measurements for 5 island populations of a certain lizard species. I want to test for each population if there is a significant difference in the ...
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8 views

Should I correct for multiple comparisons after simple main effects?

I had recently a discussion with a colleague and I can't figure out who is right. Suppose you run a study with two factors: A (level 1 and level 2) and B (Level 1, level 2 and level 3). You analyse ...
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Should this be a one-way repeated measures anova?

I'm a new phd researcher and i just completed my first set of experiments. Participants played the same game using three different control mechanisms. In the game they had to complete a series of ...
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25 views

Two-way ANOVA on the effect of gender and age on factor scores obtained through EFA?

A questionnaire consisting of 24 Likert-type questions was developed and distributed to the participants. The questionnaire had not been validated in the past, therefore, exploratory factor analysis (...
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Modelling different types of responses to a series of drug concentrations

I have been performing dose response experiments on cancer and control patients for cell counts, apoptosis (flow cytometry DAPI-AnnexinV staining), intracellular protein staining on flow cytometry and ...
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0answers
16 views

How to distinguish between interval and categorical variables, and between continuous and count data?

I need to decide what statistical test to use to analyse my data, but I cannot decide which one to use because I'm not sure what kind of variables I have. In similar papers, they all use ANOVA, but I ...
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13 views

How do I perform within subject repeated measures analysis without groups?

In an experiment I have tested participants accuracy in 2 conditions (A and B), each with the same 2 levels (1 and 2). Additionally, these participants have been scored on a test (P-Test Score) with ...
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26 views

Mixed Model ANOVA or Multiple Paired Sample T test?

I'm currently working on my research and this is the design: The aim of the research is to investigate the effectiveness of mindfulness on subjective wellbeing and perceived stress. So, 100 ...
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1answer
39 views

Further analysis after performing exploratory factor analysis

A questionnaire survey was conducted to explore underlying factors affecting pedestrian road crossing behavior. The respondents were asked to answer Likert type questions along with demographic ...
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Comparing 3 groups with ANOVA: two paired and one independent

You want to compare the number of brain cells in the following scenario:Imagine you have performed a therapy in one hemisphere of the brain (right hem) of one patient (Pt#1) while the other hemisphere ...
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11 views

How to calculate required sample size for nested 2x8 repeated measures design?

I need to calculate the sample size required for a 2x8 repeated measures design in which variable B ("condition", 8 levels) is nested in variable A ("stim", 2 levels). In our previous analysis, we ...
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32 views

Which type of ANOVA fits?

Currently researching the effects of altitude acclimation. Each person was exposed to exactly the same conditions on four consecutive days for one hour each time. A number of baseline measures were ...
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1answer
36 views

How to compare $t$-tests to $\chi^2$-tests for feature selection

I am trying to learn feature importance for an ML model. To do this I am running a univariate statistical test between each independent feature and the dependent variable I am trying to predict. The ...
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1answer
18 views

How to test for pairwise differences between factor levels while looking at an interaction with another factor?

Let's say I have a survey with questions 1 through 10 about different characteristics of animals rated from 1 to 10 and this is repeated for 5 different animals. Suppose I collect 50 surveys so my ...
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13 views

Significance testing with ordinal and continuous variables

I have a continuous normally distributed dependent variable (-1:1) and an ordinal independent variable (Low, Med, High). I want to test whether there is a difference between groups. I could use an ...
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1answer
15 views

5-way significant interaction with mixed-ANOVA, how to interpret!? (SPSS)

I am analysing results from a study which was a 2 (stimulus type) x 2 (distance) x 2 (speed) x 2 (cardiac cycle) x 2 (grouping variable-between subjects) mixed ANOVA, all of the factors have 2 levels ...
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Assessing online segment performance: prop.test or lm (ANOVA)

I some data on online performance (in terms of impressions and clicks) of a number of segments. The segments are defined by a main rule (four in total, defined in the ...
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Two-way MANOVA - No significant multivariate interaction - can I still interpret univariate interaction?

Assume that a two-way mixed (two independent variables (IVs)) MANOVA was conducted. The multivariate interaction effect of the two IVs on the dependent variables (DPs) together was not significant. ...
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4 views

Mauchly not calculated even though more than 2 levels

I have a statistical problem I need help with. But I can't find it anywhere I did a test with 31 subjects and 3 treatments. Each subject underwent each treatment in a randomized manner. I constantly ...
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9 views

How many levels is to many levels in a multiple factorial ANOVA (MANOVA)?

I performed an experiment where in which I got very good results when I perform the MANOVA analysis using 3 factors with: 3x3x9 levels. Then I tried to get a global perspective of the interactions ...
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1answer
32 views

Interpreting a main effect, in the presence of an interaction

In my analysis I have subjects whose blood pressure is measured across time, for two dose conditions (control and drug). I have used a linear mixed effect model and plotted best-fit lines of the BP ...
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1answer
21 views

One-way ANOVA controlling for session effects

I have a dataset collected from an experiment which has a simple structure that lends itself to a one-way ANOVA analysis (categorical IV, continuous DV). The data are collected over 20 experiment ...
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13 views

BCa intervals in Pairwise comparisons SPSS

In SPSS after a Two-way ANOVA analysis I have performed Pairwise Comparisons for main effects. The fact is that BCa intervals are not inversely the same when is comparing for example A-B (-2.156,5.613)...