Glossary

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

66 results found in machine learning.

Foundation Model (Large Pretrained Model, General-Purpose AI Model, GPAI)
A foundation model is a large AI model trained on broad, general-purpose data — typically at massive scale using self-supervised or unsupervised learning — that can be adapted (fine-tuned) for a wide …
Frame differencing (Temporal differencing, Background subtraction)
A computer vision technique that detects motion or changes in video by comparing consecutive frames pixel by pixel. In accessibility applications, frame differencing can identify instructor actions in…
Gesture Recognition (Gesture Detection)
The computational process of identifying and interpreting human gestures—typically hand, arm, or body movements—using sensors and machine learning algorithms. Gesture recognition systems analyze data …
Hidden Markov Model (HMM)
A statistical model used extensively in pattern recognition where the system being modeled is assumed to follow a Markov process with hidden (unobserved) states. HMMs have been foundational in both au…
Histogram of Oriented Gradients (HOG)
A feature descriptor technique used in computer vision for object detection that counts occurrences of gradient orientations in localized portions of an image. HOG captures edge and texture informatio…
Human Activity Recognition (HAR, Activity Recognition)
A field of machine learning and ubiquitous computing that uses sensor data — typically from accelerometers, gyroscopes, and other sensors in smartphones, smartwatches, or other wearable devices — to a…
Image Classification (Visual Classification, Photo Classification)
A computer vision task where a machine learning model assigns a category label to an input image based on its visual content. Image classifiers are trained on labeled example images and learn to recog…
Image Retrieval (Content-Based Image Retrieval, CBIR, Visual Search)
A computer vision technique that searches a database of images to find ones similar to a query image based on visual features rather than text metadata. In accessibility applications, image retrieval …
ImageNet
ImageNet is a large-scale visual database containing over 14 million labeled images organized into thousands of categories, widely used for training and benchmarking computer vision models. Many objec…
Individual Sign Language Recognition (ISLR, Word-Level Sign Recognition, Isolated Sign Recognition)
A machine learning task focused on recognizing individual signs from a sign language, translating single signs independently without considering surrounding context. Unlike continuous sign language re…
Instance-Level Recognition (Instance Recognition, Fine-Grained Recognition)
A computer vision task that involves distinguishing between specific individual objects within the same general category, rather than just identifying broad categories. For example, while category-lev…
Isolated Sign Language Recognition (isolated SLR, word-level sign recognition)
A sign language recognition task that focuses on identifying individual, pre-segmented signs rather than continuous signing sequences. In isolated SLR, each sign is captured as a separate video clip w…
Isolated Sign Recognition (ISR, ISLR)
A computer vision and machine learning task focused on identifying individual signs from video recordings where each video contains a single sign production, as opposed to continuous sign language rec…
K-Shot Learning (N-Way K-Shot Learning)
A machine learning paradigm where a model must learn to classify objects using only k training examples per class. In the context of accessibility, k-shot learning is significant because it enables as…
Machine Teaching (Interactive Machine Teaching)
A paradigm in human-computer interaction where non-expert users guide the training of machine learning models through interactive feedback, such as providing examples, labels, or corrections. Unlike t…
Markov Logic Networks (MLN, MLNs)
A machine learning framework that combines first-order logic with probabilistic graphical models to handle uncertainty in rule-based reasoning. In assistive technology contexts, MLNs enable context-aw…
Mel Spectrogram (Mel-frequency Spectrogram, Log Mel Spectrogram)
A visual representation of sound that maps audio frequencies onto the mel scale, which approximates how humans perceive pitch — compressing higher frequencies and expanding lower ones to match the non…
Motion History Image (MHI)
A computer vision technique that represents motion in video sequences as a single grayscale image, where pixel intensity indicates recency of movement. Brighter pixels represent more recent motion whi…
Multimodal Features (multimodal data, multimodal fusion)
Information extracted from multiple sensory channels or data types—such as combining visual (RGB), depth, audio, and skeletal data—to improve recognition accuracy. In accessibility systems, multimodal…
Named Entity Recognition (NER)
A natural language processing technique that identifies and classifies named entities in text into predefined categories such as person names, locations, organizations, quantities, and domain-specific…