Questions tagged [two-way]

For statistical models or methods used to study the effects ow two variables simultaneously, see https://en.wikipedia.org/wiki/Two-way_analysis_of_variance

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Power analysis for two-way repeated measures ANOVA

I am trying to run a post-hoc power analysis on a previously conducted study, in which the results were analysed through a two-way repeated measures ANOVA (I used a 2x2 within-subjects design). ...
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Should I use a two-way ANCOVA or three-way repeated measures ANOVA on my data?

I am trying to run a two-way ANCOVA on data from a multi-crossed design, looking at the effect of 4 treatments on the decay rates of 2 DNA target concentrations in moving water over time. Mesocosms ...
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No significant interaction in two way ANOVA, what should I do, perform independent t test or post hoc tests?

I performed experiments with two way ANOVA. One factor is 'species'(ex: 1,2,3) and another factor is 'treatment' (ex: +,-) When I carried out the two way ANOVA, only the main factor 'treatment' showed ...
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Statistical test for two factors (each multiple levels) and repeated measures

I wondered what statistical test to use in the following case: one categorical factor/condition with three levels one ordinal factor/condition with three levels one numeric response variable a small ...
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OLS interpretation – if x decreases

Suppose I have a multivariate linear regression where the coefficient on Beta1 equals 0.05. All independent variables as well as the dependent variable are in percent. So the normal interpretation is: ...
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How can I correct for multiple comparisons in two-way non-normal data (without using Bonferroni)

I'm struggling to carry out statistical analysis on my cell viability assay. The assay is widely used (it's called resazurin or alamarBlue assay), but I don't think it is analysed correctly in the ...
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Two-way mixed ANOVA write-up question

Good evening, For my study I have 12 outcomes/DVs and two different independent variables: sexual orientation groups (heterosexual, pansexual/bisexual, and lesbian/gay) and gender identity (cisgender ...
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Non-parametric equivalent of two-way repeated measures nested ANOVA

I have read the closest answers to my case in this forum and everywhere else, but still remain unclear about the best course of action. I am trying to analyze transect data from multiple locations to ...
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Non-parametric Test Choice, equivelent of two-way ANOVA [duplicate]

I am examining the impact of a treatment on spring green-up dates. The data is non-parametric. Here is an overview of my situation: I have two types (treated/untreated) of forest sites for which I ...
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Two-way mixed repeated measures MANOVA in Python or R

I compare three groups: A control group Two different clinical populations They are subjected to 6 different types of stimuli, several times each (repeated measures), and 5 dependent variables are ...
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Residuals of a 2x2 between-subjects factorial ANOVA are not normally distributed

Dependent variable: Emotional impact – measured by two ordinal variables (questions) on a Likert scale [1 (Least) to 10 (Most)] A composite mean score of the two variables was created named ...
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Two-way ANOVA (2x2) interpretation for non-significant values

I'm a statistics beginner and for my research, I'm looking into the effect participants' body image (positive/negative) and an advert model type (thin/plus-sized) have on participants' view of their ...
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Analysis of variance with two empty groups: alternative?

I have treated a species with two treatments: salinity: five different concentrations a pollutant (control and two different concentrations) organisms grown with the two lowermost concentrations of ...
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Analyzing data from a pre/post study when ANCOVA isn't possible and the denominator may be zero when calculating change scores

We have conducted an experiment on an animal model of a psychiatric disorder using a pre-treatment (PRE)/post-treatment (POST) design with two treatments resulting in 4 study groups (No treatment, ...
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The minimum number of sample size for two-way MANOVA and unequal sample sizes

I have 2 categorical IVs(2 levels in each variable) and 3 continuous DVs. One IV is teaching approach and the other one is education (a moderator). I'm going to examine the effect of the 2 IVs on DVs ...
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Two-Way anova assumptions not fulfilled

My task is to determine whether two different categorical variables (residence location (city/rural) & residence size (small/medium/large)) have a connection on one numeric variable (residence ...
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Is a 2-way ANOVA immune to Simpson's Paradox?

Sometimes continuous data is of the type that would result in Simpson's Paradox findings if groups were simply aggregated. (See, for example, "Example #2: Baseball" on this page https://www....
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Should I perform a Post Hoc analysis if I get no significant interaction in two way anova?

Hello all! I am performing a two-way ANOVA for an experiment I am doing but I reached a concern. I saw no significant interaction effect, still, I performed a post hoc TUKEY test and got significance ...
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the two step approach

I have a continuous variable which is not normally distributed i want to transform it to normal using the two step approach method in the link below: Abstract This article describes and demonstrates ...
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Separate anovas or 7 way manova?

I have 7 independent variables and two dependent variables which I think I should run 7 way manova, but this method is to complicated to compute, is running separate anovas for each dependent variable ...
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Odds ratio for an $I \times J$ table

I am trying to find a general expression for the odds ratio in a two-way table. I know for a $2 \times 2$ table odds ratio can be expressed as: $${\rm OR} = \frac{\pi_{11}\pi_{22}}{\pi_{12}\pi_{21}}.$$...
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Why is there no panel quantile regression with two-way fixed effects yet?

I have been learning the quantile regression model recently, and my understanding is (possibly wrong) that quantile regression is essentially extracting the subsamples corresponding to a certain ...
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Question on what is being repeated in this repeated measures ANOVA

I am replicating a two-way repeated measures ANOVA in a journal for practice. There are: One dependent variable density (I chose one from multiple dv presented in ...
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Event study / DiD with panel data and repeated treatment in different years for each country

I have an unbalanced panel dataset with approx. 30 countries from 1980-2000. I would like to study how political uncertainty measured by close elections affects a certain continuous variable Y, say ...
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Post-hoc test of two-way permutation ANOVA

I have a 2x2 study design to test the interaction between two drugs, with a single variable outcome. The data are very much non-parametric and it seems that a good alternative to the traditional two-...
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Post-hoc test for PERMANOVA (adonis2) of a single variable (vegan package)

I have a 2x2 study design to test for the interaction between two drugs (i.e. with or without drug1 and/or drug2), with a single continuous outcome for each combination. The data are unbalanced and ...
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Differences between nested ANOVA and two-way ANOVA, without a repeated measures structure and a small number of levels per factor

My question is rather simple, and it's not so much about R, but about how to analyse a very simple dataset. I have 6 sites, and 2 ecosystem type (3 sites per ecosystem). From each site I have 3 ...
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Two-way ANOVA: does the interpretation of a significant main effect apply to all levels of the other (non sig.) main effect if no interaction effect?

I need clarification re how to interpret the results of a two-way ANOVA modelled with an interaction effect. My results suggest that the interaction effect is not significant, and that only one of my ...
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What Statistical test would be most appropriate for comparing death counts by age in two populations?

I am not a statistician by any means, and am new to this. I have "patient" level data that has a persons death status, age, and gender. I want to compare it with the general population ...
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How to control the family-wise error rate testing simultaneous hypothesis in two-way Anova?

I guess explaining with an example would be best. Let's say we are researching which type of fertilizer and planting density produces the greatest crop yield in a field experiment. We assign different ...
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Two-way ANOVA test in R

I have some measurements of 14 animals in control group and 12 animals in treatment group (10 weeks old). After 4 weeks we repeated those measurements but most of animals have died. I left with 5 ...
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How to calculate the error terms in mixed ANOVA?

I recently came across this question and just couldn’t figure it out. I have to derive a ANOVA table from the following data: B1 B2 B3 A1 35 32 29 A2 29 28 27 A is a between-participants IV with 2 ...
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Does two-way ANOVA still works fine with unequal sample sizes?

I want to test if installing a new technology (with two different versions) can reduce water waste. I'll test the following: no installation (control), installation of new technology (version 1), and ...
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Is normality assessed in each individual group or for the entire dataset in repeated measures ANOVA?

This is probably a stupid question, but somehow I got very confused and so far I could not find a clear answer (there might be no clear answer). I have residue data in 4 different plant matrices (eg ...
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Two ways ANOVA does not show the interaction between the variables [closed]

I am doing a two-way ANOVA and I want to examine the interaction between two variables. The variables are the following: STS (Sign language knowledge) and Hearing (if they are hearing or deaf). Both ...
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How to calculate sample size for blocked-design two-way ANOVA?

Does anyone know of a good online calculator or at least a good paper that details how to calculate the needed sample size for a blocked-design two-way ANOVA experiment? I've seen a ton of references ...
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Two- or One-Way Anova?

I am having a question regarding a statistical analysis I am conducting. Let's say I have a continuous variable that I measure (Plant Weight) and I have 2 factors with 2 levels (sufficient watering/...
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Which ANOVA should I use?

Let's say I have a problem where there are two distinct groups, and within each groups, there are two more groups, leading to a total of four groups. So it's something like this: I want to run five ...
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one-sided t-test after a two-sided t-test?

I have two groups and I conducted a two-sided $t$-test. mean group 1: 3.79 mean group 2: 4.07 $p$-value: 0.0081 The $p$-value is less than $\alpha$ = 0.05, hence, I can reject the null hypothesis of ...
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How can I get LSDV estimator of a two-way dynamic panel model?

I am now trying to explain a dynamic panel data model as follow: $y_{it} = \alpha y_{i,t-1} + x_{it}'\beta + \mu_i + \lambda_t + \nu_{it}$ Here I want to compute its LSDV estimator $\tilde\beta$, ...
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Can I do a hypothesis test to see if two populations are different if there are known subpopulations within the data?

I have a continuously variable output (diffusivities) that I have measured from two different populations (say "Case 1" and "Case 2"), and I am trying to see if the two populations ...
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Calculating alpha level for Bonferroni

I have 4 null hypotheses. I want to conduct 4 two-way mixed ANOVAs (one between-subjects factor and one within-subjects factor) for each of my 4 dependent variables. I will use the same between-...
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My Design defines the Hypothesis test?

a conceptual question appear in my mind and i need help, in pratical therms, whats defines the statistical test its my hypothesis and my experimental design ? Using this example, if i am interrested ...
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Can we use `two way anova` when factors have interaction?

You should have independence of observations, which means that there is no relationship between the observations in each group or between the groups themselves. Above sentence come from https://...
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Is it apporpriate to use two way ANOVA test if I have paired data linked to single individual?

I am new in statistics. I wanted to do some statistical test to determine whether there is a difference between two samples and over the individuals. So if I have data that looks like this: ...
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Interpreting interaction from two-way anova table

I've conducted three pairwise comparisons of variables and the results were as below: ...
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Kronecker product for two way error component model

The two way Error Component Model defined as $$y_{it} = \mathbf x_{it}^\top \beta + \mu_i + \lambda_t + v_{it}$$ for $i=1,...,H$ and $t=1,...,T$ can be written in matrix notation using kronecker ...
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How to approach unbalanced data with unequal sample sizes for comparing means

I have a data with a continuous and two categorical (population and sex) variables. I want to test whether the means among the groups are significantly different. However, this is not an experimental ...
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Two way ANOVA when one independant variable is not Categorical

I am doing a test on doctors' training level and the number on duty. One IV is training level, the other IV is the number of doctors on duty. The DV is the number of patients seen. There are two ...
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Two way analysis of binary data (repeated)

I have a data set that is measuring a yes(1)/no(0) outcome across six time points and under two conditions. We have 15 participants that completed all time points under the two conditions. Disclaimer;...