statistics

random forest

A committee of decorrelated decision trees, robust and hard to overfit.
52 related articles

Description

A random forest is a machine learning method that builds a 'forest' of many decision trees and combines their predictions. Each tree is trained on a random subset of the data and considers a random subset of features at each split, which makes the trees different from each other. The final prediction is the average (for regression) or majority vote (for classification) of all trees. This ensemble approach reduces the risk of overfitting that a single decision tree often suffers from, making the model robust and accurate on new data.

History

Introduced by Leo Breiman in 2001, building on earlier work on bagging and random subspace methods.

How it works

The method creates many decision trees, each trained on a bootstrap sample (random sample with replacement) of the original data. At each node of a tree, only a random subset of features is considered for the best split, not all features. This decorrelates the trees—they make different errors. When predicting, each tree gives its output, and the forest aggregates them. The randomness ensures that no single tree dominates, and the averaging smooths out individual tree noise.

In practice

Used in finance for credit scoring, in bioinformatics for gene selection, and in remote sensing for land cover classification.

Fun fact

Random forests can estimate which features are most important for prediction without extra computation, by measuring how much each feature reduces impurity across all trees.

Concept graph →

Related articles · 52

A Greedy Flock: How Foraging Gives Rise to Collective Behavior
Picture a flock of birds gathering around a feeder that no one built. Each bird searches for food on its own, yet they all end up together. Usually, such behavior is explained by social instinct: birds want to be near their kin. But what if the flock is simply a side effect of greed?
Materials2026-08-161 minarXiv:2608.15928express
AI hunts for materials like a head chef
Hunting for a new material is like cooking without a recipe: you try, try again, and often throw things out. Previously, scientists manually flipped through papers and tested compositions one by one. Now there's a "robot chef" that reads the literature itself, mixes components, and checks what came out.
q-bio.PE2026-08-152 minarXiv:2608.14965express
A Neighbor's Calm as a Safety Signal
A lone fish sees a shadow overhead. Should it flee? If it's just a leaf, it wastes energy and gives away its position to a predator. If it's a heron, hesitation is fatal. That's the eternal trade-off of the solitary individual: quick reactions mean many false alarms, while caution means risking being eaten. In a school, it's different.
q-bio.PE2026-08-141 minarXiv:2608.14416express
How an Ecosystem Saves Itself by Losing Species
Rare species in a large community are like thin branches on a tree: a random gust can easily snap them. Even if conditions are stable, a small population simply lacks enough individuals to survive a bad season. In a new study, scientists added this factor to an ecosystem model and watched the community clean itself out.
q-bio.PE2026-08-131 minarXiv:2608.13370express
How Inheritance Division Shapes Survival
Two daughter cells receiving equal shares from the mother: that's the familiar picture of division. But what if one gets almost everything and the other just crumbs? Stochastic modeling shows that sometimes unequal division is more advantageous. Each cell stores a protective reserve that helps it weather hardships. During division, this reserve is distributed between daughters.
Quantum Physics2026-08-102 minarXiv:2608.09583express
The Noise That Helps Fix Errors
A quantum computer is like an orchestra where each musician, a qubit, plays their part but keeps hitting wrong notes. To keep the music from turning into cacophony, you need a conductor who instantly hears the off-key notes and corrects them.
Statistical Mech2026-08-102 minarXiv:2608.09714express
How Charged Particles Choose Their Crystal
In a pot of water, microscopic spheres, colloidal particles, are floating. Each sphere is coated with long polymer chains that look like a brush and carries an electric charge. If you get the temperature and solution composition right, the spheres start arranging themselves into ordered patterns — crystals.
Movement Alters Decisions
A person flips a coin to make a decision. They stand still — the coin lands heads. They take a few steps, and flip again. It would seem walking shouldn't affect the coin. But what if the walk itself changes how often they decide to simply repeat the previous toss? That's exactly what researchers tested.
Division That Doesn't Fragment Memory
Holding in mind the exact position of a pen as it's slowly moved is a routine task for the brain. For artificial neural networks, it's nearly impossible. Standard recurrent networks like GRU and LSTM tend to break continuous motion into rigid steps: the pen doesn't glide smoothly but jumps from point to point.
q-bio.PE2026-07-292 minarXiv:2607.27496express
The Backbone of Food Webs: How to Save Ecosystems in a Changing Climate
A web where lions eat zebras and hyenas finish the leftovers is not just a list of dinners. It's a survival map for an entire region. When the climate shifts, animals move, and the map tears. To understand where it will tear and where it will hold, you need to find its unchanging 'skeleton'—the connections that repeat across different places.
How Ideas Learn from Each Other
The human mind is like a construction set that builds itself. New ideas don't die with their creators: they are passed on, mixed, and selected. This process is called cultural evolution: useful inventions stick, useless ones are forgotten. That's how a ratchet works — a mechanism that only turns forward. But what exactly happens in the head when one thought displaces another?
Galaxies2026-07-242 minarXiv:2607.22835
Archipelago in the Ocean of Data: Red Points Without Color Boundaries
Two hundred forty-two thousand three hundred twenty-seven galaxies — like grains of sand on a beach. But astronomers turned this chaos into a map: the UMAP algorithm (a machine learning method) took from each galaxy eleven parameters — seven colors from optical to mid-infrared (that's photometry), magnitude…
q-bio.BM2026-07-202 minarXiv:2607.17753express
Scout proteins find genes by their energy trail
A protein slides along the DNA strand like a key along a keyring, searching for its lock. One wrong turn and a gene stays switched off. To know where a protein will grip firmly, you need to measure the strength of that grip — the binding energy.
eess.SY2026-07-161 minarXiv:2607.14606express
How to read an enemy in the sky in seconds
In combat, a pilot needs to instantly understand what an object is and what its intentions are. Conventional systems wait for complete radar data — like a goalkeeper who only reacts after the shot. The new algorithm works like an experienced goalkeeper: from the attacker's first moves, it predicts the target's maneuver.
q-bio.PE2026-07-161 minarXiv:2607.14653express
Why Genes Mess Up the Family Tree
Imagine a cookbook that gets rewritten from generation to generation. One day, the borscht recipe receives a secret ingredient from a pastry chef, and from that moment, the taste remembers not only ancestors but also a neighbor. In the Standard Model of evolution, genes behave the same way.
nlin.AO2026-07-161 minarXiv:2607.14914express
How Spite Replenishes Resources
Two gardeners haggle over water from a magical well. One proposes how many buckets to take, the other can agree or refuse. If the deal goes through, the water decreases; if not, the well gradually refills. This haggling repeats hundreds of times, and the gardeners' habits sometimes change randomly, as if they're trying new tactics.
q-bio.PE2026-07-161 minarXiv:2607.14950express
How Noise Creates Diversity
For a long time, biologists argued: if a herd of animals stably maintains a mix of aggressive and peaceful individuals, does each one alternately change behavior, or do some always fight while others always yield? In classical equations, these options are indistinguishable.
eess.AS2026-07-161 minarXiv:2607.15243express
The Illusion of Accuracy: How AI Testing in Acoustics Misleads
An AI predicting room acoustics is like a student taking an exam with a cheat sheet. If the test points are the same as the training ones, the model simply memorizes the acoustic 'fingerprint' of each position — like a student recognizing a question by the dog-eared corner.
cs.LO2026-07-151 minarXiv:2607.13531express
Chemical Soup Computes Numbers: How Reactions Became a Computer
In boiling soup, molecules collide chaotically and react. But if you measure how their concentrations change, patterns emerge. This is how carbon chemical networks work — mixtures of molecules that spontaneously 'cook' information, turning each reaction into an elementary computation. Previously they were used only for modeling nature.
eess.SY2026-07-142 minarXiv:2607.12590express
Coevolution of Agent and Environment: How an Algorithm Learns to Reshape the World Around It
Traditionally, machine learning algorithms operate in a static environment, like water flowing along a pre-cut channel without changing its shape. The new method flips this paradigm: it lets an agent simultaneously master actions and deliberately modify the very environment it inhabits.
Robotics2026-07-141 minarXiv:2607.12861express
Invisible Map of a Robot Swarm
A robot swarm is like a cloud of fireflies: each moves on instinct to wherever is freer, and chaos turns into order. For a long time, it was a mystery how coherence emerges without communication or commands. The answer came with the creation of the Response Map — a tool that, like an X-ray, illuminates the hidden logic of the machine brain.
q-bio.PE2026-07-141 minarXiv:2607.12919express
Evolution as a Tangled Web: Secrets of Intertwined Ancestries
Evolution resembles not just a tree with diverging branches, but a woven tapestry. Threads of ancestry cross when species exchange genes — for example, bacteria pass drug resistance to each other, and plants crossbreed to produce hybrids.
math.CO2026-07-132 minarXiv:2607.11325express
The Evolutionary Tangle: How to Measure Chaos in the Web of Life?
A family tree becomes a tangle if you account for adopted children and remarriages. Evolution often resembles such a tangle: although the Standard Model, the traditional view of divergent evolution where species branch like a tree, paints a neat tree of species, in reality genes travel not only by inheritance but also directly between unrelated organisms — a process…
q-bio.QM2026-07-122 minarXiv:2607.10903express
How Sand Draws a Cell's Fate
A desert where every step reshapes the terrain. Dunes settle, new slopes emerge, and the next step is dictated by what you've just trampled. That's roughly how "sandscapes" work — a mathematical model inspired by living systems.
Digital Polisher: How a Neural Network Unveils the Secrets of Binary Gravitational Lenses
Gravitational microlensing is a fascinating cosmic effect predicted by Einstein and developed by Zwicky. A massive body passing between us and a distant star bends its light like a lens, creating characteristic magnifications and distortions.
q-bio.PE2026-07-051 minarXiv:2607.04204express
Extinction in every world, but life in switching
A runner loses on both a smooth track and sticky sand. Seems hopeless. But if the surface underfoot starts changing every few seconds (track, then sand) the runner suddenly stops falling behind. He doesn't get faster; the environment just doesn't get a chance to 'crush' his weakness. That's exactly what the authors found when studying a simple predator–prey model.
How a neural network, reading weather backwards, warns of drought months in advance
At a weather station in Brazos County, Texas, rain is recorded on magnetic tape: every day, four years straight. Nine hundred millimeters in a good season, a hundred in a bad one. Then the tape falls silent. Drought creeps in without a sound — the slow fading of the earth's pulse. The standard SPI-3 index only catches on a month or two later, once the moisture is already gone.
Genes Speak Different Languages — A Neural Network Found a Common One
60 mice, 1,980 samples, 234 lung cancer patients. Behind each number lie thousands of genes. Their activity is measured to understand the disease. But the data aren’t uniform: for one patient, you assess a protein level (a continuous number), make a diagnosis (yes/no), and determine the tumor subtype (a category).
q-bio.PE2026-06-191 minarXiv:2606.21351express
How Antibodies Learn: A Map of Beneficial Mutations
The immune system is like a tireless editor, revising antibody drafts to make them stickier to viruses and bacteria. This process is called antibody maturation: random typos (mutations) arise in the genes, and natural selection keeps those that improve target capture.
q-bio.QM2026-06-112 minarXiv:2606.13475express
How a Neural Network Eavesdropped on the Noise of Life
Population growth from a distance looks like a train picking up speed: it crawls at first, then gains momentum. But look closely at the data, and the picture blurs. One measurement shows a dozen individuals, another a hundred. Classical models wipe away this scatter like annoying smudges on a lens. They assume the noise is uniform and simply ignore it.
Machine Learning2026-06-061 minarXiv:2606.08287express
A neural network that senses stress in parts of any shape
Designing machines is like cooking: you need to know exactly where the 'dough' will tear. Old computer simulations check every point on a part for hours, like measuring the entire pot to make sure the handle doesn't fall off.
Quantum Physics2026-06-021 minarXiv:2606.02986express
Machine Learning2026-05-082 minarXiv:2605.07878express
Why Some Questions Work and Others Don't
You're trying a dish at a restaurant, but you haven't seen the menu. You ask the waiter questions — too salty? what spices?—and from the answers you try to guess what kind of chef prepared it.
Biological Physics2026-05-012 minarXiv:2605.00813express
Word Mosaic: How Physics Explains the Game of Scrabble
After a game of Scrabble, the board looks like a mosaic: tiles are scattered but form a connected pattern — islands of words in a sea of empty cells. Such a pattern can be described mathematically, but usually that requires complex rules.
Galaxies2026-04-251 minarXiv:2604.23147express
Neural Network Fast-Tracks Galaxy Formation
Studying the birth of galaxies requires simulating billions of years of dark matter growth and star formation — even supercomputers handle this slowly.
q-bio.PE2026-04-231 minarXiv:2604.22122express
How a Desert Remembers Its History
Drylands are like skin cracking from dehydration. When rainfall decreases, plants don't vanish overnight: they rearrange, leaving bare patches of soil between them. These patterns are visible even from space. Scientists compared satellite images of eight arid regions, from the Sahel in Africa to Australian deserts.
Nuclear Theory2026-04-182 minarXiv:2604.16996express
How a neural network finds errors in physics textbooks
A uranium nucleus is like a tight wallet snapped shut on two halves. To make it burst and release energy (that is, to make the nucleus split) you have to climb over an energy barrier. The height of this threshold determines whether a substance is stable or ready to fall apart at any moment.
q-bio.PE2026-04-121 minarXiv:2604.10571express
Evolution by the Same Rules
Engineers improving neural networks act like breeders: they try a variant, check the result, and keep the best. They collected 935 such trials from 161 papers and measured how often a code tweak turns out beneficial, harmful, or neutral. The picture is familiar to any biologist: 68% of changes degrade performance, 19% do nothing, and only 13% yield a gain.
q-bio.PE2026-04-111 minarXiv:2604.09966express
The Landscape Ratchet: How Fragmentation Boosts Biodiversity
A landscape cut by roads or rivers into isolated patches resembles a shared apartment after partitions are installed: residents no longer bump into each other in the common hallway. Species that once competed for the same food or space now live apart. Competition weakens, and those that would have lost to pushier neighbors in a continuous landscape now survive.
Machine Learning2026-03-151 minarXiv:2603.14161express
Learning from Many Brains
A typical machine learning model looks at one object at a time: one brain, one patient, one engine. But biologists need the big picture: how the brain of a species works as a whole, not just that of a particular fish.