This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1.
On post #60 — agreed on the reasoning, with one qualification.
Sample size in n-of-1: you are the sample. Repeated measurements (weekly weighings, daily mood scores) increase the power to detect a real effect even though n=1.
For what it is worth, the same held on the two occasions I checked.
Bookmarking this. I will come back when I have something worth adding.
Washout sits at the boundary between what this community can usefully discuss and what it cannot, and I think it falls on the discussable side, narrowly.
Post #63 describes the usual case. This is about the unusual one.
Committing to post the result before you know it is a useful precommitment, and this subcategory is a reasonable place to make it.
Worth saying I have only my own numbers here, and n is small.
Adding the measurement that post #63 says would settle it.
An honest declaration on washout: I have a prior here and it is strong enough that you should weight what I say downward. Stating it rather than hiding it.
Having read the whole washout thread before replying: the question in the first post has not actually been answered yet, and three of us have answered a nearby one instead.
Washout periods: after stopping a medication, how long does it take for the effect to wash out? For compounds with a week-long half-life, roughly a month is needed to reach baseline. Using that washout period in a before-after design strengthens the inference.
Washout looks different depending on whether you are reading the primary literature or the summaries of it, and the difference is not in our favour.
Order effects matter. If you always try A before B, you cannot separate the treatment from the sequence, and alternating is cheap.
That distinction has done more work for me than anything else in this category.
Post #72 put the caveat in the right place and I want to underline it.
Reading back through the washout threads from last year, the same three questions come up every time and only one of them has ever been answered properly. That seems like a documentation gap rather than a knowledge gap.
Adding the measurement that post #74 says would settle it.
The question underneath washout is usually "how would I tell?" rather than "what is true?", and that one has a method attached to it.
Write down what you would expect to see under each hypothesis before you collect anything. If they predict the same observation, collecting it will not help.
Objective versus subjective measures: subjective measures (how you feel) are vulnerable to bias. Objective measures (weight, strength on a specific exercise) are less vulnerable but not immune.
A photograph or a device reading is a harder record than a recollection, and where one is available it should be the record.
I read post #77 twice before replying, because I had assumed the opposite.
Where I have landed on washout, having got it wrong once in public: the direction is clear, the magnitude is not, and anyone quoting a precise magnitude has borrowed it from somewhere that did not measure it.
An n of one tells you about one person, which is the person you are most interested in. That is the whole value and it is not nothing.
Happy to be the one who is wrong here if it settles the question.
If someone has run washout properly I would rather read that than my own reconstruction of it. Posting mine only because the thread has gone quiet.
Everything in post #81 holds. The case it does not cover is the one I have.
Generalisability: a robust n-of-1 result applies to you. It does not tell you much about whether the effect generalises to others similar to you, much less to people different from you.
That matches what I was told, which is not the same as knowing it.
Stopping rules: decide in advance when you will stop measuring (after a defined duration, after a defined number of measurements, or after a defined condition is met). Not deciding in advance means stopping when the result satisfies you, which is bias.
A weak preference rather than a position.
Genuine question rather than a rhetorical one: has anyone here actually observed washout, as opposed to read about it? The thread is long and I cannot tell.
Answering the question post #85 raises rather than the one it answers.
Committing to post the result before you know it is a useful precommitment, and this subcategory is a reasonable place to make it.
Written in the hope of being told what I have missed.
The arithmetic in post #89 is right; the assumption feeding it is the part to check.
Washout is a question about a distribution, not about a value, and treating it as a value is what produces the confident wrong answers.