All Questions
7,269 questions
0
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7
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Is it valid to do a repeated mesure anova when I want to compare means of a matrix question (one answer per row, 5pt likert scale, dependent sample)?
We asked participants to rate different items (matrix question, 12 Items (rows) & 5-pt Likert scale (one answer per row)). The rows were randomised in the survey.
Question: How do I compare the ...
- 1
0
votes
3
answers
65
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Unsure what stats test to use for my data: ANOVA or chi-square
I have a matrix of 17 features by 9 groups with the values being the counts for each feature appearing in that group, eg:
Grp1
Grp2
Grp3
Grp4
Grp5
Grp6
Grp7
Grp8
Grp9
F1
2
9
0
1
0
0
1
2
0
F2
3
4
0
...
1
vote
2
answers
30
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Should I conduct a multilevel for this or another analysis? Need help
I have three sources of data (teachers, parents and students) assessing students, in three waves. I want to assess all and see the differences between moments but then I also want to use variables for ...
0
votes
1
answer
48
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Bradley's liberal criterion
I'm reading an article where the authors utilized Bradley's liberal criterion to estimate the robustness of the F statistic in the context of post hoc tests.
The problem here is that they said the ...
-1
votes
0
answers
8
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what happens when a network has low closeness centrality - what happens to nodes on the periphery [closed]
I have thirty-nine nodes with closeness centrality scores but I do not know what to say about the nodes on the periphery who do not have scores.
3
votes
1
answer
46
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Calculate marginal effects for random effects model with two crossed random effects
I am trying to get effects marginal of two crossed random effects (using STAN or brms). I understand how to do it for a single random effect following McElreath's book and Kurtz's brms version of the ...
1
vote
0
answers
18
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How to Analyze and Interpret Between and Within Variance in a Dataset with Measurement Errors?
I am analyzing air pollution levels across 5 firms. For each firm, I have daily air pollution measurements taken over 5 days. My goal is to evaluate the variability of air pollution levels between ...
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0
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8
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Can MANCOVA be applied for the following parallel factorial trials?
Good morning everyone, I have a question about the validity of MANCOVA for a project. I have a factorial experiment to optimize removal efficiency "Y", considering two factors (velocity &...
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4
votes
2
answers
41
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Accounting for non-independence and autocorrelation in HGAM
I am currently trying to fit a HGAM to model differences in daily activity patterns of fish in two treatments. Data were collected with high-resolution telemetry, and I currently have estimates of ...
- 105
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0
answers
16
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Computation question for ANOVA with matrices
I'm currently studying for finals and have come across this question that I'm having trouble approaching. The linear regression model is defined as always (in this particular scenario with 2 ...
- 181
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0
answers
22
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Derive gamma-parameters from preset R^2 in mixed models
For a simulation study in R, I want to select the effect sizes according to a preset $R^2$.
Consider this two level random intercept mixed model, with one L1 predictor $X_{ij}$ and one L2 predictor $...
- 153
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0
answers
24
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When doing multiple ANOVAs, do I need to adjust the p-values?
I measured 12 blood parameters in 80 individuals and I know sex (F/M), season (start/end) and locality (A/B). So I have 12 continuous dependent variables and 3 independent variables, each with 2 ...
- 1
0
votes
0
answers
9
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Extracting individual level posterior class memebership probabilities in multilevel LCA
I am conducting a multilevel laten class analysis using the R package multilevLCA.
I have fitted the model using multiple steps (i.e. determining optimal number of classes as well as clusters). I now ...
- 1
0
votes
1
answer
36
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What model for my data?
I have a problem where we want to compare 3 treatments (a standard one against 2 new proposals). For each treatment we produce 5 objects. Each object is then divided in smaller parts and from each ...
- 1
1
vote
1
answer
75
views
Choose the right Statistical test in my case
I have a survey dataset where each participant answered 20 unique questions. I want to analyze the data statistically but am unsure which test to use: ANOVA, repeated measures ANOVA, or mixed-effects ...
- 11
1
vote
0
answers
31
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Post-hoc Analysis whith interaction but no main effects
I am reviewing a scenario where I have two factors (insecticide, herbicide) each with two levels (absent, present). There is no main effect for insecticide or herbicide, but there is a cross-over ...
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6
votes
1
answer
125
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Is there a way to forecast by subgroup without forecasting each subgroup separately?
I am trying to find an appropriate model to forecast the number of applications received at the end of a recruitment cycle based on previous recruitment cycles and the number of applications received ...
1
vote
0
answers
29
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Nested design with fixed and random effects: Is my R model correct?
I am trying to analyze a nested experimental design in R, but I am unsure whether I am approaching it correctly. I have a following data:
Set
Sample
Repet.
Response
1
1
1
y1
1
1
2
y2
1
2
1
y3
1
2
...
- 11
1
vote
0
answers
48
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Opposite results using Bayesian (STAN) vs Multilevel model (nlme). How is this possible?
My datasets contains the median wages and the cumulative installed wind-capacity for 4000 counties over a period of 20 years. The wages tend to rise over the period and the capacity tends to highly ...
- 11
0
votes
0
answers
18
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How to Forecast Sales for Sub-Locations Without Historical Proportion Data?
I have a time series dataset of total sales for a product in a store over time. This product is available in two different locations within the store: one stand near the checkout and another stand in ...
1
vote
1
answer
39
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How much missing data in the output variable is OK when using Linear Mixed Models?
I have repeated-measures data, but due to missingness, I plan to use linear mixed models. My only predictor is Time, and my outcome variable is a Happiness Score measured quantitatively. The goal is ...
- 111
0
votes
1
answer
40
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How to retrieve main group effects from GEE in R (anova?)
I want to know if the outcome variable differs across three groups. As my data includes several family members, I use a Generalized estimating equations (GEE) model in R:
...
2
votes
1
answer
111
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Why does the f-statistic change between nested anova's?
My understanding of the p-values in an ANOVA table is that it gives the significance of an additional predictor in a sequence of increasingly larger models. So I would expect the first 2 rows of an ...
- 311
2
votes
1
answer
42
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How to approach a one-way ANOVA with SOME dependence?
I am looking to compare several groups using a one-way ANOVA. Each group is independent from one-another, but the samples within each group have some dependence to one-another (i.e. some (or all) of ...
- 31
0
votes
0
answers
11
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Can I use only the block section of a center composite design for optimisation?
So I designed an experiment with 6 variables to run sequentially in a supposed closed environment automatically. However during the switch from different blocks, something went wrong and now only the ...
- 1
0
votes
0
answers
24
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Multivariate (two-way/two-factor) ANOVA post hoc tests proper significance calculation method
I would like to get a proper justification for choosing one of the three of the various methods used to determine the causes of interactions in post-hoc procedures for multivariate ANOVA. I have ...
- 333
0
votes
0
answers
54
views
Negative binomial GLM with interaction term...Anova warning?
I am running a seemingly simple model:
model<- glm.nb(PathogenLoad ~ Species*Lifestage, data = data)
The species variable has 3 levels and Lifestage has 2 ...
- 31
3
votes
0
answers
96
views
Isn't it a problem to conduct post-hoc tests based on the overall p-value from ANOVA?
Let's say that after conducting an ANOVA, I get an overall p-value smaller than 0.05 (or whatever alpha level). Following that, I decide to conduct post-hoc pairwise tests to check the individual ...
- 31
0
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0
answers
24
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Multilevel Model in R
I have data from a study in which 19 participants (9 males, 10 females) have each completed 4 jumping conditions (BW, 20, 25, 30) whilst I have measured joint level data for the hip, knee and ankle. I ...
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4
votes
1
answer
218
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Is LMM a good alternative for Repeated Measures ANOVA with Missing Data?
Our study aims to assess whether there has been an increase in overall happiness among participants who used our interventions—such as dance classes, art classes, meditation, and other resources—...
- 111
0
votes
1
answer
42
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CWC(M) in multilevel modeling
I am new to multilevel modeling and recently learned about CWC(M) by Zhang et al. (2009, https://journals.sagepub.com/doi/abs/10.1177/1094428108327450). I am running a multitlevel moderated mediation ...
- 1
0
votes
0
answers
18
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Comparing data at different locations over a time series
I have water quality data from sondes placed at different locations across a lake that collected every hour over the entirety of the summer. I want to know if there is a difference between the four ...
- 1
0
votes
0
answers
12
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No significance in omnibus test, but significant in EMM [duplicate]
I am trying to investigate the difference between the level of a protein in people with and without an injury.
The protein is a transformed variable, and normally distributed. I wanted to adjust for ...
- 117
2
votes
2
answers
121
views
Nested ANOVA in R produces warning message "Error() model is singular"
I am trying wrap my head around nested ANOVA specifically with the aov() function in R but I ran into some conceptual issues, also I believe because of inconsistencies around terminology on the ...
0
votes
0
answers
12
views
mice multilevel imputation: does specifying cluster variable ("-2" in predictor Matrix) without multilevel methods lead to cluster robust imputation?
In short: Are mice's imputations cluster robust when I only specify the cluster variable with "-2" in the predictor matrix but do not use multilevel models during imputation?
For clustered ...
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0
votes
0
answers
10
views
How to Analyze Data with Very Rare Detection Events?
I am analyzing the distribution of particles by size in several specimens. I need to determine if there is a statistical difference in mean particle count between two groups of specimens (n=50 per ...
0
votes
0
answers
12
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Looking for references/resources to help explain why a design is pseudoreplicated to a colleague
A colleague and I are working on a project which involves sampling 15 different sites, and we collected 3 replicate samples at each site (to capture spatial variability, not repeated measures at an ...
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0
votes
0
answers
31
views
How do I do significance testing in this experiment?
We have an internal search engine system similar to google. On a default config A, if we give a query, it will give 1000 results with a rank. If the same query was given again, it will again give 1000 ...
4
votes
1
answer
45
views
How to Simulate a Multilevel Predictor Variable with Both L1 and L2 Variance Components?
I'm working on simulating multilevel data where I have a predictor variable measured at Level 1 (L1), which has both L1 and L2 variance components. For example, I want to simulate a socio-economic ...
- 153
2
votes
1
answer
35
views
Reporting Hierarchical Regression Results in Abstract
I did a hierarchical regression test in a social science study looking at how two variables (A and B) and their interaction term can predict variable C. My mentor told me to write in the abstract that ...
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1
vote
0
answers
29
views
How to find out if statistical significant difference exists between 5 treatments over time
Assume I have 5 fields (F1...F5), each one treated (T) in a different manner so that F1=T1, F2=T2, ..., F5=T5. I measure a response variable in each field at different times (t) let's say from 1 to 10 ...
0
votes
2
answers
30
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null hypothesis in ANOVA model formula
I'm working with 2-ways ANOVA. So I am considering the model
Let's imagine each factor has 2 levels.
The overall Null Hypothesis (NH) are:
No effect of factor 1:
No effect of factor 2:
and no ...
- 143
2
votes
1
answer
54
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linear mixed effects models (lme): model comparison via AIC() or anova() function
I have a quick question concerning model selection for linear mixed effects models: When directly comparing AICs of two models (either including or excluding an additional fixed effect) versus ...
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3
votes
1
answer
38
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What are the advantages and disadvantages of using a one-way between subjects MANOVA versus a split-plot repeated measures ANOVA?
For example, I would like to analyse the difference in heart rate, breathing rate, height, weight, and number of hair between three species (cats, dogs, and rats). This is a nonsensical example of ...
- 331
0
votes
1
answer
33
views
Mediation models require a sigma matrix that is symmetric
I'm trying to fit the following reproducible mediation model called final. But I get an error saying:
sigma must be a symmetric matrix
Could you please advise how ...
- 397
4
votes
0
answers
32
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Anova.glm procedure - results different between Type II and Type III settings for glm but not lm?
When using Anova to determine significance of factors in general linear models it is known that type II and type III settings will produce the same results when the design is balanced.
However, when ...
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2
votes
0
answers
16
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Which estimator to choose for meta-analysis^ REML or CR2 with Wild Bootstrap?
I am following the following book: https://bookdown.org/MathiasHarrer/Doing_Meta_Analysis_in_R/multilevel-ma.html
I can't choose which estimator to choose: REML or CR2 with Wild Bootstrap.
Or maybe ...
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3
votes
1
answer
61
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How can we simulate correlated random variables that vary at different levels in a multilevel/mixed effects setting?
I am very familiar with generating correlated random variables from a multivariate normal distribution.
This question is about doing that in a multilevel setting, where variables only vary at ...
- 65.8k
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votes
1
answer
21
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Modelling a continuous covariate measured at every observation time point
I have a within-subjects design where I measure the dependent variable at 4 time points, repeated measures, in a number of participants (say 30).
To use an analogy (without getting into the specifics ...
2
votes
1
answer
78
views
General formula for mixed models
I'm trying to wrap my head around the general formula of mixed models and how it relates to the system of equations I'm used to.
The general formula read like this:
$$\mathbf{Y_{j}}=\mathbf{X_{j} \...
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