2021/09/01
Forecasting Uncertainty Is Never Too Large
Rob J. Hyndman gave a presentation titled “Uncertain futures: what can we forecast and when should we give up?” as part of the ACEMS public lecture series with recording available on Youtube.
He makes an often underappreciated point around minute 50 of the talk:
When the forecast uncertainty is too large to assist decision making? I don’t think that’s ever the case. Forecasting uncertainty being too large does assist decision making by telling the decision makers that the future is very uncertain and they should be planning for lots of different possible outcomes and not assuming just one outcome or another. And one of the problems we have in providing forecasts to decision makers is getting them to not focus in on the most likely outcome but to actually take into account the range of possibilities and to understand that futures are uncertain, that they need to plan for that uncertainty.
2020/06/07
Rediscovering Bayesian Structural Time Series
This article derives the Local-Linear Trend specification of the Bayesian Structural Time Series model family from scratch, implements it in Stan and visualizes its components via tidybayes. To provide context, links to GAMs and the prophet package are highlighted. The code is available here. I tried to come up with a simple way to detect “outliers” in time series. Nothing special, no anomaly detection via variational auto-encoders, just finding values of low probability in a univariate time series.
2019/06/16
satRday Berlin Presentation
My satRday Berlin slides on “Modeling Short Time Series” are available here. This saturday, June 15, Berlin had its first satRday conference. I eagerly followed the hashtags of satRday Amsterdam last year and satRday Capetown the year before that on Twitter. Thanks to Noa Tamir, Jakob Graff, Steve Cunningham, and many others, we got a conference in Berlin as well. When I saw the call for papers, I jumped at the opportunity to present, trying what it feels like to be on the other side of the microphone; being in the hashtag instead of following it.