# 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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### 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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### Framing the hypotheses for a two-way ANOVA

[Table showing the decrease in weights(in kgs) for 9 people taking into consideration 3 types of diet and different time periods(in number of weeks)] It is asked to apply the appropriate ANOVA ...
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### Why not include the interaction in the partial eta squared of a principal effect?

The partial eta squared of the principal effect of factor $A$ in a two-way ANOVA is defined as $$SS_A\over SS_A+SS_{error}$$ While I understand perfectly what this represents, it would somewhat make ...
29 views

### 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 ...
29 views

### 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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### How to test/ interpret two-way or three-way interaction effects with IVs and moderators?

I have a question regarding testing/ interpreting two-way or three-way interaction effects with IVs and moderators. I have 3 IVs (categorical: first has two levels, second has 4 levels, third has 6 ...
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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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### Error function in aov()

To the point, my question is How to use the Error function in aov()? What calculation has been performed in Error function? To examine the effect of treatment, I set the three groups (Group: Control,...
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### pureErrorAnova(alr3 package on R) would work for two-way factorial anova

I have a balanced 2x5 anova factorial which 4 replicates each group. I'm trying to check the Lack of fit and I came accross the pureErrorAnova - alr3 package (Im using R software). My independent ...
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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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### Two-way or three way repeated measures ANOVA with replicates

I have tried to read some papers about two-way ANOVA and repeated measures ANOVA but I just get more confused the more I read. I have a BACI study design where I have investigated 12 stations. I have ...
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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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### Research Design

Problem: Need Statistical Consulting for Methodology Section. Note: No help required with conducting or writing analyses. Only need help with finalizing the appropriate design. I am conducting a ...
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### Determining Significance in AxB Anova with repitition

I am looking to understand how the best method of determining the individual significant between my interactions would be calculated in a Two Way anova with repetitions. Based on the results of the ...
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### Segmented regression analysis wherein the breakpoints differ by variable level

I have some electrophys traces. Like many such traces, there's a leap, a bend, a gradual decline, a faster decline, then back to baseline. I'd like to do a segmented regression comparing interaction ...
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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;...
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### R survey sackage method for replicating SUDAAN proc crosstabs SEROW [closed]

I have been using SUDAAN's proc crosstabs to generated weighted crosstabs, percentages, and standard errors for counts and percentages. I'm trying to replicate this functionality in R and have gotten ...
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### What is the difference between the measurement, and within subject factor fields is in SPSS (two-way repeated measures ANOVA)?

First, I am sorry if this seems very silly, but this is the first time I do any statistical analysis. I did a study with 10 subjects and I have a couple of questions regarding the statistical ...
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### Comparing proportions of two samples in time

I am trying to compare if the proportion of one bird subspecies in a roosting area is different now from over 20 years ago. My dataset looks like following: -In 1996 birds were counted at a ...
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### Homogeneity of variances but non normal residuals of a two way ANOVA

I have a problem, actually two. I am doing a bunch two-way ANOVAs and some of them can't fullfil the assumptions, no matter what I transform the data to. Question: Does there exist a suitable non-...
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### Dummy variables in two-way ANOVA

I do not understand how to use dummy variables and the statistics underlying them. I don't need to apply this or use it in SPSS or any software. I do know that they can be used for categorical ...
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### Two way ANOVA with percent change

I have two groups of animals: "active cycle" and "inactive cycle". Within each group, there are two groups: "control" and "treated". I measured the levels of a specific receptor for each animal in ...
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### A two mixed ANOVA showed no significant interaction, but showed a statistically significant main effect of time, Do I need to run a paired T-test?

I did a mixed ANOVA with one within subjects factor with two levels 'time' and one between subjects factor (control + intervention). Its a comparison between INT or CON on scores pretraining and ...
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### Help in Two-way ANOVA with Significant Interaction

I got the following results for an experiment of fermentation to produce Butanol: ...
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### r - How to use Aligned Rank Transformed ANOVA for 2x2 non-normal data?

I'm a complete novice to stats and r so kindly bear with me. I'm testing to see if the moisture content in two plants (p and s) is affected by heat (cold and warm). The 2x2 factorial data mandates a ...
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### Are these the correct residuals to test for normality for a within-subjects 2-way anova?

I have data of an experiment where subjects performed a task under 4 conditions (A1B1, A1B2, A2B1, A2B2, where A1/A2 are the levels of factor IV1 and B1/B2 those of ...
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### Understanding, reporting and post hoc testing a 2x2 Mixed ANOVA

I one dependent variable, one between groups independent variable (intervention vs. control) and one within groups independent variable (time1 vs time2) so I am using a 2x2 mixed ANOVA. These are my ...
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### What statistical test should I use for moderation?

I am hoping to test an interaction effect, though being new to statistics/quant research in general, I am a little unsure as to which test would be most appropriate. I have read around using ...
370 views

### Unbalanced Two Way ANOVA

I am attempting to finish my stats on my Master's thesis and am having difficulties with which statistics test I should be using, and how to go about doing so. I have collected chl-a samples at 15 ...
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### Biostats two way anova in R boxplot visualisation

I am having a problem analyzing some data from a recent experiment in R. The experiment was balanced with 5 replicates in each group. It included two factors (plant type and leaf age) with 15 ...
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### Significant interaction in Mixed-design 2-way ANOVA. How to correct for multiple comparisons?

I have conducted a mixed-design two-way ANOVA (between subjects variable : 2 levels; within subjects variable : 8 levels). I have a significant main effect of between and within subject variables and ...
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### Post hoc analysis after two-way repeated measures ANOVA

I am measuring test performance at 10 different timepoints, before and after drug application. So far I ran two-way repeated measures ANOVA and determined there is a significant timepoint, drug, and ...
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### Two way ANOVA, no difference between tests based on type I vs type II sums of squares

I'm learning about two way ANOVA possibly with interaction. I'm following this tutorial http://www.sthda.com/english/wiki/two-way-anova-test-in-r This is their code. ...
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### Which statistical test to compare between and within differences?

I have two groups of patients with two different treatments applied, Treatment A vs Treatment B. In addition, I have measurements on 4 different time points for an ordinal variable (scale 1 to 4, ...
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### 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 ...
2k views

### Understanding the Anova (car package) output in r

I am running a two-way anova test using Anova from car package. My data looks like this: ...
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### Mixed-Design ANOVA Confusion: Do I separate my treatment Column?

In this particular study, I had 40 experimental subjects which were randomly allocated to 2 treatment groups. After the initial treatment, each where randomised to receive 2 other treatments. So the ...
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### Refitting the ANOVA model?

I have performed a Two way ANOVA, for one response and two categorical variables. I had found that EDA with a plot of means shows that there might be an interaction between my categorical varibles ...
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### How to analyze non-normal DVs from two-way repeated measures (4x4) design

In my study twenty subjects experienced all four levels of both factors (4x4 design). The residuals for my DVs were not normally distributed as would be required for the two-way repeated measures ...