Glossary

Searchable terminology from accessibility, web standards, and related fields.

80 results found in Machine Learning.

Large multimodal model (LMM, Multimodal AI, Vision-language model)
An artificial intelligence model capable of processing and generating content across multiple modalities, such as text, images, and audio. Examples include GPT-4V and Gemini. In accessibility applicat…
Layer-wise Relevance Propagation (LRP)
Layer-wise Relevance Propagation (LRP) is an explainable AI technique that attributes a neural network's prediction back to its input features by propagating relevance scores layer by layer from the o…
Learning Vector Quantization (LVQ)
A supervised machine learning algorithm used for pattern classification, commonly applied in brain-computer interface systems to classify EEG signals. LVQ works by creating a set of reference vectors …
Linear Discriminant Analysis (Fisher Discriminant Analysis, Fisherfaces)
A statistical method used in pattern recognition and machine learning that finds a linear combination of features to best separate two or more classes of objects. In the context of face recognition, L…
LoRA (Low-Rank Adaptation)
A parameter-efficient fine-tuning technique, introduced by Hu et al. in 2022, in which a large pretrained neural network is specialised by training only a pair of small low-rank matrices that modify s…
Mapping by Demonstration
A personalisation technique for gestural and sensor-based interfaces in which the system learns the relationship between user input (movement, breath, gaze) and output (sound, visuals, commands) from …
Meta-learning (Learning to Learn)
A branch of machine learning where models are trained to learn new tasks from very few examples by leveraging knowledge gained from previous tasks. In accessibility applications, meta-learning enables…
Mixture of Experts (MoE)
Mixture of experts is a neural network architecture that routes each input through a small subset of specialist subnetworks ('experts') rather than activating the whole model. A gating network decides…
Neural Radiance Field (NeRF)
An implicit neural representation of a 3D scene, introduced by Mildenhall et al. in 2020, in which a small neural network is trained to map any 3D coordinate and viewing direction to a colour and dens…
Neural Vocoder
A deep-learning model that synthesises audio waveforms from intermediate acoustic representations such as mel-spectrograms or discrete speech units. Examples include HiFi-GAN, WaveNet, WaveGlow, and S…
Object recognition (Object detection, Image classification)
A computer vision task in which a system identifies and labels objects within images or video, often using deep learning models trained on large datasets. For blind and low-vision users, object recogn…
On-device Recognition (On-Device Inference, Edge Recognition)
Performing pattern recognition - such as sign language recognition, speech recognition, or computer vision - locally on the user's device rather than by sending input to a remote server. On-device rec…
Open-Vocabulary Detection (Open-Vocabulary Object Detection, OVD)
A class of computer vision object detection models that accept arbitrary text queries at inference time rather than being restricted to a fixed set of pre-trained classes. Instead of only recognizing,…
OpenPose
An open-source computer vision library developed by Carnegie Mellon University that detects human body, hand, facial, and foot keypoints in real-time from images or video. OpenPose extracts 25 body ke…
Parameter-Efficient Fine-Tuning (PEFT, Lightweight Fine-Tuning)
Parameter-efficient fine-tuning is a family of techniques (LoRA, adapters, prefix tuning, prompt tuning) that adapt a large pretrained model to a new task or domain by updating only a small fraction o…
Part-of-Speech Tagging (POS Tagging, Grammatical Tagging)
Part-of-speech tagging is the natural-language-processing task of labelling each word in a text with its grammatical category — noun, verb, adjective, and so on — using context from surrounding words.…
Perceptual Linear Prediction (PLP, PLP Coefficients)
Perceptual Linear Prediction (PLP) is an acoustic feature extraction technique used in speech processing that models human auditory perception. PLP analysis applies psychoacoustic principles including…
Perplexity (Language Model Perplexity)
A standard metric for evaluating language models that measures how well the model predicts a sample of text. Mathematically, perplexity is the inverse probability of the test set, normalised by the nu…
Pointwise Mutual Information (PMI)
A statistical measure used in natural language processing to quantify the strength of association between two words based on how much more frequently they co-occur in a corpus than would be expected b…
Pose estimation (Body pose estimation, Human pose estimation)
The computational process of determining the position and orientation of a person's body joints and limbs from sensor data such as cameras, depth sensors, or inertial measurement units. In accessibili…