Decision Tree Learning
Reviews: Optimal Decision Tree with Noisy Outcomes
The setup is original and I see high value in the persistent-noise assumption worked out by the authors. I do have one main question to the authors and while I recommend this paper to be accepted based on significance and appearance of correctness, I do expect a very strong answer on this point for the score to remain high after rebuttal phase. The authors state in their experiment: "To ensure every pair of chemicals can be distinguished, we removed the chemicals that are not identifiable from each other." Well, for significance of the present work, we also need to know how the algorithms are going to behave in the worst-case if there are symmetries and this kind of preprocessing step is omitted. Note that the user would be happy with being presented a set of hypotheses and a certificate that no further test is available to distinguish among them.
Model Monitoring in the Absence of Labeled Data via Feature Attributions Distributions
Model monitoring involves analyzing AI algorithms once they have been deployed and detecting changes in their behaviour. This thesis explores machine learning model monitoring ML before the predictions impact real-world decisions or users. This step is characterized by one particular condition: the absence of labelled data at test time, which makes it challenging, even often impossible, to calculate performance metrics. The thesis is structured around two main themes: (i) AI alignment, measuring if AI models behave in a manner consistent with human values and (ii) performance monitoring, measuring if the models achieve specific accuracy goals or desires. The thesis uses a common methodology that unifies all its sections. It explores feature attribution distributions for both monitoring dimensions. Using these feature attribution explanations, we can exploit their theoretical properties to derive and establish certain guarantees and insights into model monitoring.
Reviews: Partitioning Structure Learning for Segmented Linear Regression Trees
Originality: The paper is fairly original in that it proposes a new tree-splitting criterion that seems to work very well when the leaves are linear models rather than constants. It also provides a novel application of several pieces of previous work, including LASSO and random forests. There are adequate citations of related work. Quality: I did not carefully check the math or read the proofs in the supplemental material, but I did not observe any technical mistakes. There is not much discussion of the limitations of their approach.
Reviews: Partitioning Structure Learning for Segmented Linear Regression Trees
The paper proposes and investigates how to learn tree structure for linear regression trees based on a conditional Kendall's tau statistics with theoretical analysis.The ideas were new and generally satisfying to reviewers. While some reviewers would have liked to see even more experiments and experimental comparisons and details, other reviewers felt that the author response about the experiments was satisfying.
Reviews: A Debiased MDI Feature Importance Measure for Random Forests
I am updating my score from 7 to 8. --- # Originality The main contributions are all original. While the take-home message of the study is in retrospect simple and obvious ( compute MDI importances on out-of-bag samples), the paper provides an original analysis that explains and justifies this modification of the computation of MDI importances. Some remarks however: - I would have appreciated a controlled experiment where G0(T) can be computed exactly in order to empirically appreciate the (supposed) tightness of the bound. More specifically, what if A1 and A2 are not satisfied? In real-word setups, A1 is very unlikely to hold.
Reviews: A Debiased MDI Feature Importance Measure for Random Forests
The paper studies theoretically the bias of the popular MDI importance measures in the presence of noisy features and proposes a very simple practical solution to reduce it. Two reviewers are very enthusiastic about the paper, even more so after reading the authors' response. One reviewer has several valid concerns about missing links between theory and practice but still recommends acceptance. I therefore recommend accepting the paper. The author are asked to take into account the reviewers comments when preparing the final version of their paper and, in particular, to address the specific request of reviewer 2 (to clarify how MDI-oob is computed).
coverforest: Conformal Predictions with Random Forest in Python
Meehinkong, Panisara, Ponnoprat, Donlapark
Conformal prediction provides a framework for uncertainty quantification, specifically in the forms of prediction intervals and sets with distribution-free guaranteed coverage. While recent cross-conformal techniques such as CV+ and Jackknife+-after-bootstrap achieve better data efficiency than traditional split conformal methods, they incur substantial computational costs due to required pairwise comparisons between training and test samples' out-of-bag scores. Observing that these methods naturally extend from ensemble models, particularly random forests, we leverage existing optimized random forest implementations to enable efficient cross-conformal predictions. We present coverforest, a Python package that implements efficient conformal prediction methods specifically optimized for random forests. coverforest supports both regression and classification tasks through various conformal prediction methods, including split conformal, CV+, Jackknife+-after-bootstrap, and adaptive prediction sets. Our package leverages parallel computing and Cython optimizations to speed up out-of-bag calculations. Our experiments demonstrate that coverforest's predictions achieve the desired level of coverage. In addition, its training and prediction times can be faster than an existing implementation by 2--9 times. The source code for the coverforest is hosted on GitHub at https://github.com/donlapark/coverforest.
Review for NeurIPS paper: Estimating decision tree learnability with polylogarithmic sample complexity
Additional Feedback: The paper is not interesting enough for a competitive conference. It is good to have these results in the literature, but I suggest to send it to a journal. Having read the reviews, and following the discussion, I still think that this does not below in a competitive conference. Indeed, as the authors stress in their response, the power of the result is due to the specific algorithm developed here. Nevertheless, I cannot be excited by it, given the monotonicity assumption and the fact that it applies only to the uniform distribution setting. I agree that it's an interesting result, but I think that it's not interesting enough nor important enough for a top conference.
Review for NeurIPS paper: Estimating decision tree learnability with polylogarithmic sample complexity
The submission got four reviews that were quite polarised in their recommendations, with two against accepting and two strongly in favour. The disagreement did not concern the technical quality of the paper. The reviewers agree that the theoretical work in this paper has been very competently performed and in the context of the problem the authors consider, the results are interesting and advance the state of the art. The disagreement is over whether the results are significant enough for NeurIPS or would be more appropriate for a specialised theory conference. The main objections against accepting are (i) the results are not surprising, (ii) the assumptions (monotonicity and uniform distribution) are strong and (iii) the overall computational complexity is high.