X times per Y is incorrect in average

[gruvw]

Pre-submission checklist

• I am submitting a bug report, not a feature request.
• I have searched for similar issues, but did not find any matches.

Description

TL;DR: The X times per Y system does not guarantee an average corresponding to user expectations due to the sliding window implementation.

If I want to perform a given task let's say two times per week, the current implementation allows for doing it only ~1.1 times per week on average.

On most weeks (12 out of 14) the user performed the task only once. Though they have kept their streak and are increasing their score. This is quite misleading for a user who wanted to perform the task twice per week.

Note: I was a little bit hesitant to choose between a Feature Request tag or a Issue tag as this was probably intentional though I think it can be quite misleading to users that don't expect it.
So the current behavior feels like an issue to me but the solution to it might be a new feature.

Steps to reproduce

(see picture)

System information

N/A

App Version: Android 2.2.1

Potential solutions

1. Add a "fixed window" check box (keeps user input simple) when selecting the habit frequency to force the completion of the task X times in the Y days fixed window.

2. Use a running average computation based streaks system where you compute the score based on how close you are to the average in the sliding window.

3. ? other ideas ?

[ZornHadNoChoice]

This is quite misleading for a user who wanted to perform the task once per week.

Typo: twice.

Also, I want to add that the week window should follow the natural order (Monday to Sunday in OP's case). The same should be true for months (so the interval length matches the months) and years. This will probably require to change the implementation, since from what I remember, they convert all intervals to days (so month->30 days).

[KyleSCraig]

This is specifically an issue for streaks. The percentage will never near 100% like this.

I'm a user who doesn't really care about streaks, and generally prefers the per 7 days (rolling) to per week (aligned with calendar).

[TheOtherDoctor]

I want to add a focus on an effect which is, (I think) related to the annoyance described in this issue, and is for me much more striking - but since I think it is related, I hesitated to put it as a separate issue...

As an example: When I intend to, say, read a book for 10 hours a week and I do read 1 hour on Monday and 9 hours on Tuesday, I'd expect these two days getting colored since my target is achieved. But actually only days with 2 hours reading on that very day get colored, thus in the overview it looks like Monday I did nothing on that topic. I'd like to easily see in the overview where I ignored a habit for too long; this kind of reminder is actually THE key feature of the whole app for me.

As I understand, in the daily overview an entry gets marked when it would assert goal achievement if it would be continued with same intensity over the whole time constantly. This is not value-adding for me, I want to track especially habits with non-constant rates, like exercises which can be done only twice a week. For me, the current algorithm always results in confusions. As a side effect, those progress rings left of the text are mostly rather off reality for me.

For me it makes most sense to mark the status colored on any day which contributed (so value is >0) and keeps target within the current timeframe. So when the current target timeframe is fine, mark the entries of the contributing days with the color. Especially do not hide days in which I contributed to a goal which is given in a non-daily manner.

(oh now I see my comment likely matches better into related #1829 - and BTW, I refer to app version 2.2.0 running on Android 12 on a Galaxy S7)

[tom-f-oconnell]

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