Technology and the built world

Private press movement

The private press movement was a tradition of artisanal book production beginning with William Morris's Kelmscott Press in London in 1891, and flourishing through the early twentieth century.

Private spaceflight

Private spaceflight, also called commercial space flight, is spaceflight funded and operated by private companies, from suborbital tourism to commercial ISS crew and cargo transport.

Private VLAN

A private VLAN (PVLAN) is a Layer 2 technique that partitions a VLAN into isolated subdomains, so devices sharing one IP subnet cannot communicate directly with each other.

Privatisation of the English water industry

The privatization of the English water industry transferred ten regional water authorities to private companies floated on 1 September 1989 under Margaret Thatcher's government, creating the regulator Ofwat.

Privilege escalation

Privilege escalation, also called elevation of privilege, is a cyberattack that gains permissions beyond those a user or process is authorized to hold, typically by exploiting vulnerabilities or misconfigurations.

Privilege separation

Privilege separation is a security design technique that splits a program into a small privileged monitor and unprivileged components handling untrusted input, best known from OpenSSH.

Prix de Rome (architecture)

The Prix de Rome in architecture (Grand Prix de Rome d'architecture) was a French state competition, held from 1720 to 1968, funding winners' residencies in Rome.

Sep 21, 2026

Priya Vashishta

Priya Vashishta is an American materials scientist who holds the Fluor Chair in Engineering at the University of Southern California, known for billion-atom molecular dynamics simulations of ceramics and nanomaterials.

Prize money (naval)

Prize money was a payment to naval officers and crew from the court-condemned value of enemy ships and cargo, shaping naval warfare from the sixteenth to the nineteenth century.

PRM800K

PRM800K is an OpenAI dataset released in May 2023 with 800,000 human step-level correctness labels for model-generated solutions to MATH problems, the reference dataset for training process reward models.

PRNET

PRNET, the Packet Radio Network, was an experimental wireless packet-switched network funded by DARPA from 1973, connecting mobile computers over broadcast radio as one of the early Internet's three original networks.

Pro Display XDR

Pro Display XDR is a 32-inch 6K professional reference display by Apple, introduced in 2019 and discontinued in 2026 in favor of the Studio Display XDR.

Pro Football Focus

Pro Football Focus (PFF) is a sports analytics company founded in 2006 by Neil Hornsby that grades every player on every play of every NFL and college football game.

Pro Tools

Pro Tools is a digital audio workstation developed by Avid for music, film, and broadcast audio. It is available in four editions: Intro, Artist, Studio, and Ultimate.

Proálcool

Proálcool (Programa Nacional do Álcool) was a Brazilian government program launched in 1975 to replace petroleum fuels with ethanol from sugarcane, becoming the world's largest biofuels program.

Probabilistic clustering

Probabilistic clustering is a family of unsupervised methods that fits a probability model, typically a finite mixture model, to data and assigns each point to clusters through posterior membership probabilities.

Probabilistic constellation shaping

Probabilistic constellation shaping (PCS) is a signal-processing technique for digital modulation in which low-energy QAM constellation points are sent more often, improving spectral efficiency and noise tolerance.

Probabilistic context-free grammar

A probabilistic context-free grammar, also called a stochastic context-free grammar, is a context-free grammar with a probability on each rule, so parse trees can be ranked to pick the most probable parse.

Probabilistic design

Probabilistic design is an engineering methodology that treats loads, material strengths, and dimensions as random variables, sizing structures so their calculated failure probability meets a target reliability.

Probabilistic logic programming

Probabilistic logic programming (PLP) is a family of methods combining logic programs with probability distributions to represent uncertain relational knowledge, underlying languages including PRISM, ProbLog, and LPADs.

Probabilistic Movement Primitives

Probabilistic Movement Primitives (ProMPs) are a robot learning framework that represents a movement skill as a probability distribution over whole trajectories, introduced by Paraschos, Daniel, Peters, and Neumann at TU Darmstadt in 2013.

Probabilistic neural network

A probabilistic neural network (PNN) is a feedforward network introduced by Donald Specht in 1990 that classifies inputs through kernel density estimation and Bayes' rule.

Probabilistic risk assessment

Probabilistic risk assessment (PRA) is a structured method that quantifies the likelihood and consequences of failures in complex engineered systems, used widely in nuclear regulation.

Probabilistic roadmap

A probabilistic roadmap (PRM), also called the probabilistic path planner, is a sampling-based motion planning algorithm that builds a graph of collision-free robot configurations and searches it for paths.

Probabilistic solar forecasting

Probabilistic solar forecasting predicts future solar irradiance or photovoltaic power output as a probability distribution rather than a single value, quantifying uncertainty for grid operators, utilities, and market decisions.

Probability hypothesis density filter

The probability hypothesis density (PHD) filter is a recursive Bayesian algorithm for multi-target tracking, introduced by R.P.S. Mahler in 2003, that propagates the first-order moment of the multi-target posterior and avoids data association.

Probably approximately correct learning

Probably approximately correct (PAC) learning is a mathematical model of learning from examples, introduced by Leslie Valiant in 1984, requiring small error with high probability.

Probationary driver licence

A probationary driver license is a restricted license for newly tested drivers, the middle stage of graduated driver licensing in countries including Australia, Canada, and the UK.

Probing classifier

A probing classifier is a small supervised model trained on a frozen neural network's internal activations to predict properties like part of speech, introduced by Alain and Bengio in 2016.