Scientific method in AI
Be able to formulate a falsifiable hypothesis, design a controlled experiment and report the uncertainty.
Prerequisites
Intuition
ML research has a reproducibility problem: many reported improvements disappear when somebody reruns them with the same seeds, the same baseline tuning and more datasets. The method that protects you:
- Question → hypothesis that can be falsified, written before the experiment.
- Control: only one thing changes. The baseline gets as much hyperparameter tuning as the new method.
- Variation: at least 3–5 seeds; report the mean ± std or a CI. One seed is an anecdote.
- Several datasets: an improvement on one dataset is often noise.
- Ablation: remove each component — which one is doing the work?
- Report negative results and everything you tried, not just what worked.
Common faults: the test set used for choosing, an undertuned baseline, cherry-picked seeds, the metric switched afterwards, «significant» with no interval.
Interactive
Scrutinise a claim: «Our new optimiser gives 1.2 pp better on CIFAR-10 than Adam.»
The questions you ask:
- How many seeds? What is the std between seeds for Adam? (Often ~0.3–0.5 pp → 1.2 could be 2σ, or it could be noise.)
- Did Adam get the same lr search?
- How were the epochs and early stopping chosen — on the test set?
- Does it work on ImageNet, on text?
- Is there code, are there seeds and an exact configuration?
If the answers are missing the claim is not wrong — it is untested. Apply the same scrutiny to your own results before you show them to anyone.
Mastery means
- Formulates a falsifiable hypothesis and a controlled experiment for an ML question
- Reports with uncertainty, several seeds and a baseline
- Recognises the common methodological faults in ML papers
Sign in to do the exercises and build your mastery up.
Sources
- arXiv — Deep Reinforcement Learning that Matters — arXiv (open access; licence per article)
- arXiv — Show Your Work: Improved Reporting of Experimental Results — arXiv (open access; licence per article)