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Showing posts with label Supervised Learning. Show all posts
Showing posts with label Supervised Learning. Show all posts

Tuesday, March 01, 2022

Automating Data Science: Prospects and Challenges

 Long, insightful piece, good insights,  somewhat technical, but useful.   A favorite topic we experimented with since very early days.

Home/Magazine Archive/March 2022 (Vol. 65, No. 3)/Automating Data Science/Full Text

 By Tijl De Bie, Luc De Raedt, José Hernández-Orallo, Holger H. Hoos, Padhraic Smyth, Christopher K. I. Williams

Communications of the ACM, March 2022, Vol. 65 No. 3, Pages 76-87 10.1145/3495256

--> Given the complexity of typical data science projects and the associated demand for human expertise, automation has the potential to transform the data science process.

Key insights: 

• Automation in data science aims to facilitate and transform the work of data scientists, not to replace them.

• Important parts of data science are already being automated, especially in the modeling stages, where techniques such as automated machine learning (AutoML) are gaining traction.

• Other aspects are harder to automate, not only because of technological challenges, but because open ended and context-dependent tasks require human interaction.

Introduction

Data science covers the full spectrum of deriving insight from data, from initial data gathering and interpretation, via processing and engineering of data, and exploration and modeling, to eventually producing novel insights and decision support systems. Data science can be viewed as overlapping or broader in scope than other data-analytic methodological disciplines, such as statistics, machine learning, databases, or visualization

To illustrate the breadth of data science, consider, for example, the problem of recommending items (movies, books or other products) to customers. While the core of these applications can consist of algorithmic techniques such as matrix factorization, a deployed system will involve a much wider range of technological and human considerations. These range from scalable back-end transaction systems that retrieve customer and product data in real time, experimental design for evaluating system changes, causal analysis for understanding the effect of interventions, to the human factors and psychology that underliehow customers react to visual information displays and make decisions.

As another example, in areas such as astronomy, particle physics, and climate science, there is a rich tradition of building computational pipelines to support data-driven discovery and hypothesis testing. For instance, geoscientists use monthly global landcover maps based on satellite imagery at sub-kilometer resolutions to better understand how the earth’s surface is changing over time [50]. These maps are interactive and browsable, and they are the result of a complex data-processing pipeline, in which terabytes to petabytes of raw sensor and image data are transformed into databases of automatically detected and annotated objects and information. This type of pipeline involves many steps, in which human decisions and insight are critical, such as instrument calibration, removal of outliers, and classification of pixels.

The breadth and complexity of these and many other data science scenarios means that the modern data scientist requires broad knowledge and experience across a multitude of topics. Together with an increasing demand for data analysis skills, this has led to a shortage of trained data scientists with appropriate background and experience, and significant market competition for limited expertise. Considering this bottleneck, it is not surprising that there is increasing interest in automating parts, if not all, of the data science process. This desire and potential for automation is the focus of this article.

As illustrated in the examples above, data science is a complex process, driven by the character of the data being analyzed and by the questions being asked, and is often highly exploratory and iterative in nature. Domain context can play a key role in these exploratory steps, even in relatively well-defined processes such as predictive modeling (e.g., as characterized by CRISP-DM [5]) where, for example, human expertise in defining relevant predictor variables can be critical.  .... '

Friday, January 03, 2020

Upside Down Reinforcement Learning

New to me, in DSC, about new ways to look at reinforcement learning, see also posts on IRL.  See also other links to Inverse Reinforcement Learning.  How closely are these related?   Reading.

Reimagining Reinforcement Learning – Upside Down      Posted by William Vorhies 

Summary:  For all the hype around winning game play and self-driving cars, traditional Reinforcement Learning (RL) has yet to deliver as a reliable tool for ML applications.  Here we explore the main drawbacks as well as an innovative approach to RL that dramatically reduces the training compute requirement and time to train.

Ever since Reinforcement Learning (RL) was recognized as a legitimate third style of machine learning alongside supervised and unsupervised learning we’ve been waiting for that killer app to prove its value.

Yes RL has had some press-worthy wins in game play (Alpha Go), self-driving cars (not here yet), drone control, and even dialogue systems like personal assistants but the big breakthrough isn’t here yet.  ....

RL ought to be our go-to solution for any problem requiring sequential decisions and these individual successes might make you think that RL is ready for prime time but the reality is that it’s not.

Shortcomings of Reinforcement Learning

Romain Laroche, a Principal Researcher in RL at Microsoft points out several critical shortcomings.  And while there are several, the most severe problems to be overcome Laroche points out are these:

“They are largely unreliable. Even worse, two runs with different random seeds can yield very different results because of the stochasticity in the reinforcement learning process.”
“They require billions of samples to obtain their results and extracting such astronomical numbers of samples in real world applications isn’t feasible.”

In fact, if you read our last blog closely about the barriers to continuously improving AI, you would have seen that the increasing compute power necessary to improve the most advanced algorithms is rapidly approaching the point of becoming uneconomic.  And, that the most compute hungry among the examples tracked by OpenAI is AlphaGoZero, an RL game play algorithm requiring orders of magnitude more compute than the next closest deep learning application.

While Laroche’s research has lately focused on the reliability problem and he’s making some headway, if we don’t solve the compute requirement problem RL can’t take its rightful place as an important ML tool.

Upside Down Reinforcement Learning (UDRL) 


Two recent papers out of AI research organizations in Switzerland describe a unique and unexpected approach to this by literally turning the RL learning process upside down (Upside Down Reinforcement Learning UDRL).  Jürgen Schmidhuber and his colleagues say:

“Traditional Reinforcement Learning (RL) algorithms either predict rewards with value functions or maximize them using policy search. We study an alternative: Upside-Down Reinforcement Learning (Upside-Down RL or UDRL), that solves RL problems primarily using supervised learning techniques.”    ... '