Experimental design is the methodological study of how experiments should be designed to maximize the scientist's ability to make inferences about the causal effect of an independent variable on a dependent variable.
Questions tagged [experimental-design]
138 questions
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votes
3 answers
Track users after they go from a webpage to an app
I'm running an A/B test on a web page. Users aren't authenticated on the webpage, so there's no user ID to track them. On the webpage, there are links to Android/iOS app stores where users can download or open the app.
After users download and open…
Leo Jiang
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4
votes
1 answer
Random assignment of treatments to half of a group
I am in the process in randomly assigning treatments for an experiment. I have four sites (Site1, ... Site4) where 12 experimental units (e.g., 1 ... 12) are replicated four times (e.g., 1 ... 4). For each replicate, I have randomly assigned one of…
Todd D. Johnson
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How can I specify a generator and factor using the FrF2 or qualityTools package in R?
How can I specify a generator and factor using the FrF2 or qualityTools package in R?
The fractional factorial experiment is 2^{k-p} where k = 5 (factors), p = 1, and I = ABCD how generator, wherein the D factor is confused. Thus, D =…
bbiasi
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3
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1 answer
Response Surface Modeling and Optimization in Python: Analogous to rsm in R?
I wonder if there are modules in Python that support Design of Experiments, Response Surface Modeling and Optimization. R has a number of libraries, such as rsm which helps you define a Design and then evolve it given outcomes to approach closer…
user8270077
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1 answer
Randomizing a split-plot (and other classical designs) in R
My question is whether any R packages out there provide function(s) that make it reasonably easy to randomize a standard experimental design that may involve crossed factors, nesting, and/or blocking.
For concreteness, show me specifically how to…
Russ Lenth
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3
votes
2 answers
How to experimentally determine the scheduling quantum of a process/thread?
Just to head off any comments to the effect of "why do you need to know this??": This is just a puzzle I was curious about, not something I need to do for any practical reason.
Given a typical POSIX system[1], how would you design an experiment to…
Brennan Vincent
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1 answer
How do you implement experiments with conditional branching in PsychoPy Builder?
Many behavioural experimental designs in psychology/neuroscience require conditional branching (e.g. only proceed to the test phase if a requisite performance level has been reached in an initial practice phase). PsychoPy’s Builder view allows one…
Michael MacAskill
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3
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4 answers
CSS & Javascript Effect: arraning characters justified with different spacing between letters. Mousemove influenced
I have a two words "Word" and "Arrangement" with various spacing inbetween those characters.
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r
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r
matt
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matt
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3
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1 answer
Use of permute package to calculate all permutations in a blocked design
I want to calculate all permutations of a blocked design suitable for a Friedman test. Consider the following example:
thedata <- data.frame(
score = c(replicate(4,sample(1:3))),
judge = rep(1:4,each=3),
wine = rep.int(1:3,4)
)
Four…
Joris Meys
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3
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1 answer
Is there a way to create $2^n$ factorial designs in R (similar to minitab)?
I am working on creating a $2^n$ design (not randomized). I have done $2^5$ by hand, but I must now do $2^7$ and $2^8$. I know in Minitab there's a design generator that will list out all of the treatments / factors but I do not have access to…
doesleuth
2
votes
1 answer
How to create synthetic data based on dataset with mixed data types for classification problem?
I am trying to build a classification model, but I don't have enough data. What would be the most appropriate way to create synthetic data based on my existing dataset if I have numerical and categorical features?
I looked at using Vine copulas like…
gmh
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2
votes
1 answer
Sample size calculation for experimental design
I have three treatments (Wild type, Mutant1 and Mutant2); I request inputs on how to decide the sample size that would be statistically significant (alpha <0.05) with high statistical power (1-beta=0.8).
Questions
I understand that we need the…
Arijit
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votes
1 answer
How to compute the confidence interval of the Difference in Differences method using Python?
I'm trying to analyze the total active minutes per user before and after an experiment. Here I've included the associated user data before and after the experiment - variant_number = 0 indicates control group while 1 means treatment group.…
Alexander S. Chang
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Replicating a repeated measures compound symmetry structure from SAS to R using lme
I'm trying to replicate an analysis in a paper by Milliken (https://sci-hub.tw/10.1016/s0169-7161(03)22007-1, section 8) from SAS code to R. I'm quite stumped to be honest. It's a split plot repeated measure design where the correlation structure…
2
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2 answers
Assign control vs. treatment groupings randomly based on % for more than 2 groups
Piggy backing off my own previous question python pandas: assign control vs. treatment groupings randomly based on %
Thanks to @maxU, I know how to assign random control/treatment groupings to 2 groups; but what if I have 3 groups or more?
For…
jeangelj
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