# Simple exponential smoothing model **URL:** \ **Category:** KNIME Analytics Platform\ **Created:** [October 9, 2016, 5:44pm UTC](https://forum.knime.com/t/simple-exponential-smoothing-model/5170 "2016-10-09T17:44:16Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![hperros](https://forum-cdn.knime.com/letter_avatar_proxy/v4/letter/h/aca169/32.png) [@hperros](https://forum.knime.com/u/hperros)\ **Post date:** [October 9, 2016, 5:44pm UTC](https://forum.knime.com/t/simple-exponential-smoothing-model/5170/1 "2016-10-09T17:44:16Z")
I am using the Moving Average icon to apply the simple exponential smoothing model, and it is asking me for a window size. Unless I am horribly mistaken, there is no window size... instead one has to find the optimum value of alpha.   ---
**Author:** ![Iris](https://forum-cdn.knime.com/user_avatar/forum.knime.com/iris/32/14_2.png) [@Iris](https://forum.knime.com/u/Iris)\ **Post date:** [October 10, 2016, 9:39am UTC](https://forum.knime.com/t/simple-exponential-smoothing-model/5170/2 "2016-10-10T09:39:37Z")
Yes, you are right. I was in this node using a trick I found online. I calculate alpha as 2/(k+1) where k is the windowsize. this is how you can control alpha using the "window size". The formulas can be found in the Node Description as well. Best, Iris ---
**Author:** ![hperros](https://forum-cdn.knime.com/letter_avatar_proxy/v4/letter/h/aca169/32.png) [@hperros](https://forum.knime.com/u/hperros)\ **Post date:** [October 11, 2016, 4:29pm UTC](https://forum.knime.com/t/simple-exponential-smoothing-model/5170/3 "2016-10-11T16:29:31Z")
Ha !! I would have never thought of that !!! Thanks-- Harry ---
**Author:** ![TheLeo](https://forum-cdn.knime.com/letter_avatar_proxy/v4/letter/t/85f322/32.png) [@TheLeo](https://forum.knime.com/u/TheLeo)\ **Post date:** [November 18, 2021, 7:08am UTC](https://forum.knime.com/t/simple-exponential-smoothing-model/5170/4 "2021-11-18T07:08:30Z")
@Iris So based on this formula if I set as window size = 1 then alpha should also be 1? In that case the result should be the same as using the naive model. However what I’m getting is the same output as the input. Am I missing something? Right now it calculates like this: ```auto Simple_exponential_0 = v_0 EMA(v,n) = Simple_exponential_n = alpha*v_n + (1-alpha)*Simple_exponential_n-1 ``` From my understanding now this is not correct and should be `alpha*v_n-1 + (1-alpha)*Simple_exponential_n-1` since otherwise the function will return the input if alpha is set to 1. ---
**Author:** ![TheLeo](https://forum-cdn.knime.com/letter_avatar_proxy/v4/letter/t/85f322/32.png) [@TheLeo](https://forum.knime.com/u/TheLeo)\ **Post date:** [November 19, 2021, 9:07am UTC](https://forum.knime.com/t/simple-exponential-smoothing-model/5170/5 "2021-11-19T09:07:42Z")
For the record: [Exponential smoothing - Wikipedia](https://en.wikipedia.org/wiki/Exponential_smoothing) → Right now it uses the general exponential smooting formula and not the simple exponential smoothing. ---
**Author:** ![Iris](https://forum-cdn.knime.com/user_avatar/forum.knime.com/iris/32/14_2.png) [@Iris](https://forum.knime.com/u/Iris)\ **Post date:** [December 3, 2021, 6:56pm UTC](https://forum.knime.com/t/simple-exponential-smoothing-model/5170/6 "2021-12-03T18:56:53Z")
So basically, setting window size to 1 just does not make a lot of sense here, but why should we change the function because of it? A window size of 1 also for other models will return the input. ---
**Author:** ![system](https://forum-cdn.knime.com/uploads/default/original/1X/ab3ccf34482a0329361734a18199390177204f15.png) [@system](https://forum.knime.com/u/system)\ **Post date:** [June 23, 2023, 8:21pm UTC](https://forum.knime.com/t/simple-exponential-smoothing-model/5170/7 "2023-06-23T20:21:31Z")