concept

parameter

A variable in a model that is adjusted during learning to improve performance.
63 related articles · 1 formulas

Description

A parameter is a variable in a model that is adjusted during learning to improve performance. In machine learning, parameters are the internal coefficients that the model tunes to map inputs to outputs. For example, in a neural network, parameters are the weights and biases of connections between neurons. The process of learning involves iteratively updating these parameters to minimize the difference between predicted and actual outcomes.

History

The concept of adjustable parameters in models dates back to early statistics and least-squares fitting in the 19th century. In machine learning, the backpropagation algorithm, popularized in the 1980s, made it practical to tune millions of parameters in neural networks.

How it works

During training, the model makes predictions, compares them to known answers, and calculates an error. An optimization algorithm, such as gradient descent, then adjusts the parameters in the direction that reduces the error. This is repeated over many examples until the model performs well. The number of parameters can range from thousands in simple models to billions in large language models, and the way they are tuned determines the model's ability to generalize to new data.

In practice

Parameters are central to all machine learning systems, from image recognition and natural language processing to scientific models that predict molecular properties or discover new materials.

Fun fact

In physics, the 'no-hair theorem' for black holes is analogous to the idea that a model's behavior depends only on a few parameters (mass, charge, spin), not on the details of what fell in.

Concept graph →

Formulas

$$J_{k\alpha}(\tau_{\mu+1}) = J_{k\alpha}(\tau_\mu) - \eta \frac{\partial \epsilon(\tau_\mu)}{\partial J_{k\alpha}(\tau_\mu)}$$
Parameter update proportional to learning rate times error gradient.
What is in the formula
J_{k\alpha}variableparameter being updated at iteration — parameter
\tau_\muvariableiteration step index — iteration index
\etavariablelearning rate, step size — learning rate
\epsilonvariableerror or loss function — loss function
\frac{\partial}{\paroperatorcomputes the gradient of the error with respect to the parameter — partial derivative

Related articles · 63

Reward as a Gas Pedal: Why It Gets Harder to Press with Age
A banknote taped to the finish line makes your hand fly faster. In the lab, that banknote was replaced with a 50-pence coin, and the finish line with a target on a screen. The researchers recruited 28 young people and 28 older adults, seated them at a robot handle, and asked them to steer a cursor toward the target. Sometimes they were paid for speed and accuracy, sometimes not.
Chemical Physics2026-08-211 minarXiv:2608.21322express
Counting Protein Jitters in Seconds
A protein in a cell doesn't hang motionless like a mannequin in a store window. Its atoms are constantly jiggling, stretching, and bending, like a plucked guitar string that keeps vibrating after you strum it. To understand how a protein works, you need to know how tightly each part holds onto its neighbors.
A Translator That Can't Keep Up with Speech: How a Neural Network Accelerates Gravitational-Wave Astronomy
Imagine a simultaneous interpreter in a room where two people are speaking: they must keep up with both meaning and intonation, but if the speech is too fast, only a paraphrase remains. That's roughly how scientists feel as the stream of gravitational waves from black hole and neutron star mergers grows, while precise signal calculations lag behind.
q-bio.BM2026-08-191 minarXiv:2608.18604express
How Protein Engineers Learn from Mistakes
A protein engineer is like a chef trying to make a dish that is tasty, healthy, and cheap all at once. Change one ingredient, and you risk ruining another. In the past, computer assistants could only evaluate protein properties one at a time, missing how they are connected.
Monroe: A Molecular Model with In-Context Probabilistic Inference
An interpreter gets distracted by every rustle in the hall, and a one-hour meeting stretches into two. Similarly, molecular foundation models learn the language of molecules from vast corpora, but each new conversation requires fine-tuning. Monroe changes the rules: it doesn't learn a new language but instantly finds common meaning from a few examples.
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.
math.NT2026-08-012 minarXiv:2608.00615express
Numbers Hide Patterns
In 1998, mathematician David Boyd noticed something strange. He was studying the Mahler measure of polynomials, a quantity that gauges the "complexity" of their roots, and found that for a family of curves, it always equals a special rational number times the derivative of an L-function.
Galaxies2026-07-242 minarXiv:2607.22812
Stellar2026-07-193 minarXiv:2607.17348
SpecFANN: Lightning-Fast Sketch of a Star's Spectrum
An artist makes a quick charcoal sketch, and the face in the portrait is already recognizable. Astrophysicists face a similar challenge: the spectrum of a star is its individual portrait, revealing temperature, composition, and gravity.
Signal Processing2026-07-161 minarXiv:2607.14597express
Self-Taught Algorithm: How to Hear a Melody from Noise
Reconstructing a full picture from fragments is like discerning an orchestra's melody in a noisy hall. Such challenges arise in photometry, where a star's brightness is recovered from faint twinkling. Traditional methods need precise noise information, which is almost always unknown.
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.
eess.SY2026-07-151 minarXiv:2607.13387express
A Smart Navigator That Doesn’t Trust Itself
A typical tracking program resembles a navigator steering a ship by the stars. But as soon as the sky clouds over, coordinates drift, and entropy (a measure of uncertainty) builds up in the data. The new algorithm gets a ‘co‑pilot’ — a module that monitors how confident the main navigator is.
eess.AS2026-07-151 minarXiv:2607.13408express
How AI Stopped Mixing Up Sounds in a Script
Models that turn text into audio are good at recreating single sounds, but get confused when the script has several in a row. For example, the script might call for a ring, then footsteps, then a door slam. The generator might shuffle events, so the listener hears footsteps before the ring.
cs.SD2026-07-151 minarXiv:2607.13477express
AI Judges Listen Not with Ears, but with Labels
Automatic speech judges are algorithms that evaluate pronunciation and emotions. However, they often work like a food critic who delivers a verdict after reading the menu but not tasting the dish.
eess.AS2026-07-141 minarXiv:2607.12529express
Hearing Aids Learn to Taste Sound
Traditional hearing aids resemble a chef who cooks from a recipe blindly. They analyze the sound chaos from the microphone and amplify speech based on it. In a noisy café, this approach often errs. The new system behaves like an experienced cook: first processes the signal, then samples the result.
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.
Signal Processing2026-07-141 minarXiv:2607.12744express
Position-savvy neural network improves connectivity
In a kitchen with gas burners, each heats differently. If the cook moves the pots, food may burn. Just so in a wireless network: the antenna-burners and user-pots require precise placement. Ordinary neural networks don’t distinguish positions, treating all burners as identical. So they struggle to estimate signal quality or adjust transmission.
math.OC2026-07-141 minarXiv:2607.12775express
Smart Acceleration: Teaching the Power Grid to Think Faster
Power systems with solar panels and wind turbines are like a chess game: cloud cover and load changes are the opponent's moves, impossible to foresee. To maintain balance, operators used to run through dozens of scenarios (uncertainty) — that took too much time and computing power.
Machine Learning2026-07-131 minarXiv:2607.11091express
Neighbor molecules improve prediction accuracy
Predicting the properties of a new molecule is like guessing the flavor of an unfamiliar dish. The program works like an experienced chef: it “tastes” similar molecules whose properties are already known, and based on their “flavor,” it refines its guess.
eess.AS2026-07-131 minarXiv:2607.11260express
Sound Concentrate: Transmitting Speech Without Redundant Bits
The standard way of digitizing speech: taking volume readings thousands of times per second. It's like tasting broth with a teaspoon: each sip is watery, with almost no detail. The data stream swells, though the substance is minuscule. Scientists proposed first "simmering down" the audio signal.
math.OC2026-07-131 minarXiv:2607.11344express
Taming Chaos: How Algorithms Predict the Future
Complex machinery, from drones to surgical robots, sometimes behaves like a wild mustang: full of disorder and whims, where the slightest touch triggers a storm. Instead of rote memorization of formulas, the new method observes the system like a horse breaker.
q-bio.PE2026-07-131 minarXiv:2607.11520express
How Chance Drives Evolution
Evolution flows like water. In a wide river, changes are smooth and slow, while a mountain stream churns with every stone. Population size and mutation rate set the channel: broad and calm, or narrow and rapid-filled.
q-bio.QM2026-07-092 minarXiv:2607.08902express
A Hormonal Assistant with a Flair for Math
Inside each of us, invisible clocks are ticking. They control the release of cortisol — the hormone that helps us wake up in the morning, cope with anxiety, and keep our immune system on its toes. In adrenal insufficiency, these clocks break down: the body can't produce the right amount of cortisol on its own.
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.
Neurons Reveal Their Secrets in Minutes, Not Hours
A neuron is like a complex musical instrument. To understand how it responds to a touch, you used to have to connect to each string directly — a delicate, slow procedure that only works for individual cells.
cs.PF2026-07-033 minarXiv:2607.02945
Straightening Graph Paths: How Meta Sped Up Neural Network Training by 63%
Recommendation systems that decide which post you’ll see next run on deep neural networks made up of thousands of operations — intricate computation Graphs (blueprints of operations on data). These systems are living, ever-evolving Dynamical Systems: the slightest architecture change cascades through the entire graph.
econ.EM2026-07-013 minarXiv:2607.01429
The Data Watershed: How a Simple Yes/No Switch Reveals Multidimensional Models
On a topographic map, raindrops choose their path: falling on one slope, they flow into River A; on the other, into River B. An observer sees only the winding rivers (the response variables Y) and knows which slope the water came from (the instrument Z), but cannot see the drops themselves (the unobserved factors ε).
Squealer: When the Model Squeals, Rejecting Your Data
Statistical models are an attempt to stretch a perfect mathematical web over the uneven landscape of data. When a model resists, it emits tension, but we've grown accustomed to ignoring it. Researchers spend hours staring at residual plots, trying to guess where the model is 'coming apart at the seams.' Squealer translates this resistance into sound.
Optics2026-06-201 minarXiv:2606.21945express
Neural Networks That Have Internalized the Laws of Nature
Ordinary neural networks learn from examples, like a person memorizing tunes by ear. But networks with physical laws embedded from the start resemble a musician who knows notes and harmony: they can play a new piece from just a few chords. Instead of mindless memorization, they use equations like energy conservation or motion.
How to Design the Perfect Therapeutic Peptide: Three Properties at Once
An engineer tunes an antenna: pull one segment, the frequency drifts; change the angle, the gain drops. Developing therapeutic peptides (short protein chains) works much the same way.
How the Brain Learns to Predict Without Cues
A neural network, like a sheet of graph paper, receives homogeneous signals at its input, and draws its own coordinate grid. Initially, connections between inputs and network cells form a gentle hill: the response is strongest at the center and fades toward the edges.
Materials2026-06-061 minarXiv:2606.08148express
How Clever Sampling Teaches Metal to Predict Strength
A chef doesn't waste ingredients cooking the whole dish to check the taste: they just taste a drop of sauce. The same logic underlies the "information matching" method for predicting metal strength. Instead of expensive calculations of every atom's behavior, scientists "taste" only simple indicators linked to plasticity — a metal's ability to bend without breaking.
cs.CE2026-06-051 minarXiv:2606.07258express
How to Test a Predictor Without Knowing the Answer
A lab sends a robot a list of a thousand candidate molecules for a new drug. The predictor robot, trained on old data, gives each one a 'fit or no fit' score. But when the list comes from an unfamiliar area, a different virus or a rare tumor, the robot starts to get confused. Its confidence stays high, while actual hits drop to zero.
Quantum Physics2026-06-021 minarXiv:2606.02986express
The Brain Saves Memory Like a Cashier at Rush Hour
A supermarket cashier at rush hour doesn't memorize every scanned item: they keep the running total in their head and watch the queue. The brain allocates its resources similarly: the expensive, precise cortex (responsible for deliberation) and the simpler, economical subcortical nuclei (where habits live) work in tandem.
Why We're Different in the Morning and Evening
Every morning you pick up the same mug, but the coffee tastes either bitter or just right. It's not about the coffee, and not about your character. Inside us, an invisible panel with dozens of sliders is constantly shifting: fatigue, hunger, anxiety, hormone levels.
Statistical Mech2026-05-092 minarXiv:2605.09148express
How to Tune a Molecular Motor Without Losing Your Mind
Imagine a factory where hundreds of tiny assembly lines run nonstop. Each line is a molecular motor that converts chemical fuel into motion. To make the motor go faster or in the right direction, an engineer tweaks the settings — the shape of parts, the strength of interactions.
Chemical Physics2026-04-292 minarXiv:2604.27070express
Neural Network Learns to Read Molecules by Their Carbon Signature
Every carbon atom in a molecule carries a passport — the energy with which its deepest electrons sit in their orbitals. This energy is sensitive to neighbors: add an oxygen nearby or a double bond, and the number in the passport changes. Chemists have long measured such energies with X-rays, but calculating each new molecule takes hours of machine time.
General Relativity2026-04-282 minarXiv:2604.26011express
The Gravitational Orchestra Loses Its Rhythm
A figure skater glides across the ice, gradually moving toward the center. Their trajectory isn't a perfect spiral: sometimes they catch the rhythm of the music and add an extra turn, slightly changing their speed. That's roughly how a small black hole behaves when it falls into a supermassive one.