Domain Knowledge and the New “Turn Your Data Into Gold” Rush
Jan 29, 2020
A colleague wrote to me recently and asked if Eigenvector was considering rebranding itself as a Data Science company. My knee-jerk response was “isn’t that what we’ve been for the last 25 years?” But I know exactly what she meant: few people have heard of Chemometrics but everybody has heard about Data Science. She went on to say “I am spending increasing amounts of time calming over-excited people about the latest, new Machine Learning (ML) and Artificial Intelligence (AI) company that can do something slightly different and better…” I’m not surprised. I know it’s partly because Facebook and LinkedIn have determined that I have an interest in data science, but my feeds are loaded with ads for AI and ML courses and data services. I’m sure many managers subscribe to the Wall Street Journal’s “Artificial Intelligence Daily” and, like the Stampeders on Chilkoot Pass pictured below, don’t want to miss out on the promised riches.
Oh boy. Déjà vu. In the late 80s and 90s during the first Artificial Neural Network (ANN) wave there were a slew of companies making similar promises about the value they could extract from data, particularly historical/happenstance process data that was “free.” One slogan from the time was “Turn your data into Gold.” It was the new alchemy. There were successful applications but there were many more failures. The hype eventually faded. One of biggest lessons learned: Garbage In, Garbage Out.
I attended The MathWorks Expo in San Jose this fall. In his keynote address, “Beyond the ‘I’ in AI,” Michael Agostini stated that 80-90% of the current AI initiatives are failing. The main reason: lack of domain knowledge. He used as an example the monitoring of powdered milk plants in New Zealand. The moral of the story: you can’t just throw your data into a ML algorithm and expect to get out anything very useful. Perhaps tellingly, he showed plots from Principal Components Analysis (PCA) that helped the process engineers involved diagnose the problem, leading to a solution.
Another issue involves what sort of data is even appropriate for AI/ML applications. In the early stages of the development of new analytical methods, for instance, it is common to start with tens or hundreds of samples. It’s important to learn from these samples so you can plan for additional data collection: that whole experimental design thing. And in the next stage you might get to where you have hundreds to thousands of samples. The AI/ML approach is of limited usefulness In this domain. First off it is hard to learn much about the data using these approaches. And maintaining parsimony is challenging. Model validation is paramount.
The old adage “try simple things first” is still true. Try linear models. Use your domain knowledge to select sample sets and variables, and to select data preprocessing methods that remove extraneous variance from the problems. Think about what unplanned perturbations might be affecting your data. Plan on collecting additional data to resolve modeling issues. The opposite of this approach is what we call the “throw the data over the wall” model where people doing the data modeling are separate from the people who own the data and the problem associated with it. Our experience is that this doesn’t work very well.
There are no silver bullets. In 30 years of doing this I have yet to find an application where one and only one method worked far and away better than other similar approaches. Realize that 98% of the time the problem is the data.
So is Eigenvector going to rebrand itself as a Data Science company? We certainly want people to know that we are well versed in the application of modern ML methods. We have included many of these tools in our software for decades, and we know how to work with these methods to obtain the best results possible. But we prefer to stay grounded in the areas where we have domain expertise. This includes problems in spectroscopy, analytical chemistry, chemical process monitoring and control. We all have backgrounds in chemical engineering, chemistry, physics, etc. Plus collectively over 100 man-years experience developing solutions that work with real data. We know a tremendous amount about what goes wrong in data modeling and what approaches can be used to fix it. That’s where the gold is actually found.