Questions tagged [experiment-design]
The study of how to structure an information-gathering exercise where variation is present.
2,040 questions
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Feedback on a plan for a multi-level model?
I am planning an analysis for an experiment I am working on and would appreicate some feedback on whether my multi-level model specification makes sense (I am new to this type of statistics).
I'm ...
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What is the design effect factor for an experiment with crossed random intercepts?
I want to know what is the design effect factor of a crossed study like this where we have:
N=100 participants
15 items
Each participant assigned to treatment or control
Each participant does 7 ...
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How to design a minimal test (sample size + combinations) when two components both affect accuracy?
I’m trying to design an experiment for a system where two different components both contribute to the final accuracy, and I can only test a small subset of all possible combinations.
A concrete ...
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Analyzing full factorial experiments: pros and cons of running a model with two climate factors vs one climate factor?
I have a full factorial experiment with 4 treatments: ambient (control), drought, warmed, and warmed & drought. I sampled these treatments 4 times: pre-drought, peak drought, post drought, and ...
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Comparing pretest and posttest results when sample sizes and samples differ
I have a 14-question pretest answered by 30 students from across an entire school, and a 14-question posttest (not identical questions, but mostly similar) answered by 21 students from a single closed ...
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Power of t-test with unequal sample sizes: GPower and MESS::power_t_test do not converge?
I've created two item sets with 24 items each, that I expect to differ along my outcome variable. To test this assumption before using the items in future studies, I'm planning to recruit human ...
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Experimental design choices and how to answer them with Bayes
so I'm new to Bayesian statistics, just read the basics and trying to figure something out. In my research design I have 4 participants and 2 independent information ranges, where an optimum would ...
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Does a fully deterministic Pocock & Simon minimization affect variance estimation and inference validity (ignoring selection bias)?
I have a question about covariate-adaptive allocation in clinical trials.
Suppose we use a Pocock and Simon minimization procedure without any random component: that is, a fully deterministic ...
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Cronbach alpha for grouped binary choices in a conjoint experiment
For simplicity, let's assume I run a conjoint where each respondent is shown eight scenarios, and, in each scenario, they are supposed to pick one of the two candidates. Each candidate is randomly ...
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Only one hypothesis?
I was wondering if it's ok to only have one hypothesis for a research experiment? Advisors have suggested for me to add a few more, but I worry they might muddy the findings from my first one. Do ...
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Power analysis for a factorial design with a binary outcome
I am planning a study with a factorial design (e.g., 2×2 or 3×3), but my outcome variable is binary (yes vs. no). Most tutorials I’ve found on power analysis for factorial ANOVA assume a continuous ...
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Is it necessary to adjust the p-value for multiple dependent variable hypotheses-tests even when I'm using Tukey?
So, supposing I'm carrying out a field experiment (agricultural data), and I'm interested to understand how four plant genotypes affect three dependent variables (yield, height, and number of leaves).
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poor parameter recovery in brms from simulated vigniette experiment
I design a vigniette experiment about social norms: There is a social-media post about reducing meat consumption which varies the actor (stranger, friend, relatie), the amount of the reduction (no ...
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How to compare ranked data (factor) from multiple independent experiments in R?
I have multiple independent experiments where in each of the experiments five subject's lung capacity were tested and ranked in order from highest (1) to lowest (5). For specific reasons, I only have ...
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Model(s) for paired and nested experiment
I am planning a field experiment consisting of reducing the population of a predator species to evaluate how this would affect the abundance of its prey species. As you can see in the image below, the ...
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