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
96
questions
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5 views
two-way repeated measures ANOVA and long_db format
Good morning everybody
Here I show a dataset I'm performing a statistical analysis on. Aside the meaning names of most remarkable variables are indicated:
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3
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2answers
40 views
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 ...
4
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1answer
27 views
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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0answers
31 views
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 ...
1
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1answer
47 views
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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0answers
12 views
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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0answers
16 views
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 ...
2
votes
1answer
33 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/...
0
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1answer
24 views
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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2answers
33 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 ...
0
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0answers
21 views
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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0answers
11 views
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 ...
2
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1answer
21 views
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 ...
0
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0answers
18 views
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-...
0
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1answer
23 views
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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0answers
23 views
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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0answers
38 views
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 ...
1
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1answer
35 views
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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0answers
69 views
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 ...
1
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1answer
25 views
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:
...
2
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2answers
47 views
Interpreting interaction from two-way anova table
I've conducted three pairwise comparisons of variables and the results were as below:
...
4
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1answer
45 views
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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0answers
34 views
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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0answers
15 views
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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0answers
14 views
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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2answers
450 views
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 ...
1
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1answer
33 views
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 ...
1
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1answer
61 views
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;...
0
votes
1answer
74 views
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 ...
0
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1answer
30 views
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 ...
1
vote
1answer
153 views
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 ...
1
vote
1answer
74 views
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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1answer
1k views
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 ...
0
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0answers
101 views
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 ...
0
votes
2answers
168 views
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 ...
0
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1answer
301 views
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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0answers
523 views
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 ...
2
votes
1answer
103 views
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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0answers
1k views
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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0answers
260 views
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 ...
0
votes
1answer
447 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 ...
0
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1answer
441 views
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 ...
0
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0answers
44 views
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 ...
0
votes
1answer
68 views
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 ...
2
votes
1answer
85 views
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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0answers
22 views
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, ...
0
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1answer
50 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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0answers
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:
...
0
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0answers
38 views
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 ...
2
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0answers
51 views
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
...
