Washout with a one-week half-life: the arithmetic posts 31–60
This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1.
Collapsed as off-topic by two members at trust level 3 or above
That is the distinction I keep failing to hold on to. Written down now.
Building on post #30 rather than restating it.
Order effects matter. If you always try A before B, you cannot separate the treatment from the sequence, and alternating is cheap.
Adding it because I spent an afternoon working it out and nobody should have to twice.
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.
Everything in post #33 holds. The case it does not cover is the one I have.
The failure mode on washout is boring rather than dramatic. It is almost always the step everyone assumes was done correctly because it is too simple to get wrong.
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.
I would call the community position on washout likely rather than established, and I would be comfortable defending that hedge.
Adding a data point of agreement rather than a data point.
I read post #36 twice before replying, because I had assumed the opposite.
Summarising the washout thread so far, since it is long and the answer is buried: the first reply has the method, the fourth has the correction to it, and the rest is people agreeing at length.
A washout period between conditions is what stops one bleeding into the next, and its length should be set by the half-life rather than by convenience.
This follows post #41 rather than contradicting it.
Two sentences on washout and then I will stop, because the rest is speculation and the thread is better without mine.
What is documented is narrow. What is inferred from it is broad. The gap between them is where every argument here lives.
Coming back to post #41, because the follow-up matters more than the original answer.
A definition problem is doing most of the work in this washout discussion. Once the term is pinned down I suspect the disagreement mostly goes away and what is left is small.
A rolling mean over several days is far more informative than any single reading for anything that varies day to day, which is nearly everything.
That has held every time I have looked, which is not the same as always.
On post #41 — agreed on the reasoning, with one qualification.
An observation about washout that I cannot explain and am posting anyway, on the principle that unexplained observations are more useful public than private.
Picking up post #45: that is the part I would want checked first.
My understanding of washout is a few years old and may have been superseded. If it has been, I would genuinely like to know rather than keep repeating it.
Helpful, and short, which on this subject is harder than long.
Multiple outcomes measured without a primary one means something will move. Nominate the primary in advance and report the rest as secondary.
On washout, I would rather understate and be corrected upward than overstate and be quoted. That is a house style here and it is a good one.
Reading this washout thread as someone who came in with a fixed view: the third and seventh replies moved me and the confident ones did not.
Adding the measurement that post #48 says would settle it.
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.
Distinguishing three things in the washout discussion that keep getting used interchangeably: the observation, the proposed mechanism, and the recommendation that gets attached to both.
The strongest argument against my own position on washout, stated as well as I can state it, since nobody else has yet.
The arithmetic in post #53 is right; the assumption feeding it is the part to check.
It does not tell you about anybody else, which is why aggregating these accounts does not produce evidence of the kind people want it to.
That is one dataset and I would not build a rule on it.
Answering the question post #54 raises rather than the one it answers.
A note on scope: what I am saying about washout applies to the case in the first post and I would not extend it further without checking.
A photograph or a device reading is a harder record than a recollection, and where one is available it should be the record.
I think the washout question is answerable and has not been answered, which is a more optimistic position than most of this thread.
This is the sort of exchange that makes the archive worth searching.
On washout, the part that usually goes wrong is that the question is asked as though it has one answer. It has a range, and the width of the range is the interesting bit.
If you can post the two or three numbers you are working from, several people here will check the arithmetic rather than argue about the conclusion.