Research can be complicated. Not only can the concepts be difficult, the questions lengthy, and the methods complex – the terms used to describe things are often anything but intuitive.

While the questions you ask – and the concepts you use – depend on your individual research needs, we strive to make the methods as straightforward as possible. Our research platform is built to enable advanced human behavior research to be carried out as effectively as possible.

This however leaves the terms (and endless acronyms) to be tackled. With this in mind, we’ve put together our own biometric research dictionary, a resource to help you quickly refresh your memory, or to learn new terms by.

This list will be continually updated, and is available as a downloadable PDF here.

Alpha waveA type of brain wave detected by EEG. In the range of 8-15 Hz.
Angular velocityThe speed at which the angular position of the eye changes over time.
AOIArea of Interest. A defined area that is examined with the use of eye tracking.
ArousalRefers to physiological arousal, the extent to which an individual is alert and active.
Beta waveA type of brain wave detected by EEG. In the range of 16-31 Hz.
BiasSkewed perception. Problematic for research that relies on subjective views, as these can be biased and therefore not concordant with reality.
CalibrationA process by which sensors are attuned to the individual user, to account for anatomic and / or physiological differences between individuals.
Cognitive workloadA level of mental effort. Increased cognitive workload means an increased amount of mental processing.
Core / basic emotionsCommonly referred to as seven core, or basic emotions that are universally found.
Corrugator superciliiA muscle of the face, located at the end of the eyebrow near the nose. Activation causes frowning.
Delta waveA type of brain wave detected by EEG. In the range of <4Hz.
DistractionAn ABM EEG metric. Refers to the amount that the respondent is distracted, according to the measured brain activity.
DrowsinessAn ABM EEG metric. Refers to how drowsy a respondent is, based on their brain activity.
ElectrodeA device that detects electrical activity. Used with EEG, GSR, EMG / fEMG, and ECG.
EngagementAn EEG metric. A measure of how cognitively engaged an individual is.
ETEye Tracking
FEFacial Expression
Focus groupsA scenario in which people are gathered to discuss a topic (this could be related to a specific subject, an experience, or anything else). Focus groups are often used to provide a consensus opinion about something.
ECGElectrocardiography (measurement of the heart’s electrical activity).
EDAElectrodermal Activity (measurement of the electrical activity of the skin caused by sweat gland activity – also referred to as GSR).
EEGElectroencephalography (measurement of the electrical activity of the brain).
EMGElectromyography (measurement of the muscles).
FACSFacial Action Coding System. One of the most prevalent guides for systematically assessing facial expressions, and the associated emotional content.
fEMGFacial Electromyography (measurement of the muscles of the face).
Frequency domainA way to assess certain signals – how prevalent specific signal frequencies are.
Frontal asymmetryAn EEG metric. A difference in activity across the frontal hemispheres of the brain. Increased left-frontal activity (relative to right) is associated with approach, while increased right-frontal activity (relative to left) is associated with withdrawal.
Gaze mappingAn eye tracking analysis method. Allows comparisons of multiple unique views of a stimulus by relating each to a reference image.
GSRGalvanic Skin Response (measurement of the electrical activity of the skin caused by sweat gland activity – also referred to as EDA).
GSR peaksAn increase above a defined level (a threshold) of electrical activity measured from the skin.
HeatmapAn eye tracking analysis method. A visualization of the amount of attention directed to elements within a scene.
HRVHeart Rate Variability. A measure of how much the heart rate varies. Increased variability is associated with a relaxed state, while decreased variability is associated with increased stress.
HzHertz, a standard frequency unit. One Hertz is equal to one cycle or repetition per second.
LatencyThe duration of time that passes between an event and response.
MVCMaximum Voluntary Contraction. Used with EMG to baseline the signal.
Peaks per minuteA GSR metric. The frequency of GSR signals that pass above a threshold (per minute).
PhasicThe GSR signal above physiological baseline.
PlanogramVisual representations of a store or product. This can be purely image-based or in VR.
Poincare plotA graphical representation of HRV over a period of time.
PPGPhotoplethysmography (an optical measurement of blood flow).
PupillometryA measure of the dilation of pupils. Increased pupil size is associated with increased arousal (and vice versa).
Quantitative / qualitativeTerms used to describe different types of research methods. Quantitative is associated with discrete measurements (numbers related to the amount of fixations, for example), while qualitative refers to detailed subjective information.
QRS complexThe prototypical heart beat signal. Each letter refers to a distinct part of the change in electrical activity of the heart.
RatioAn eye tracking metric. The amount of respondent’s that looked at a defined part of an image.
Recovery timeAn eye tracking hardware specification. The amount of time it takes for an eye tracker to detect the eye (for example, after blinking).
RMSSDRoot Mean Square of the Successive Differences. An equation for calculating HRV.
RR intervalThe duration between the peak of each successive heart beat.
SaccadesRapid movement of the eyes between fixation points
Sampling rateThe rate at which information is collected by a sensor. Commonly stated as Hz.
Smooth pursuitA smooth movement of the eyes when tracking a moving object
StimulusSensory information that is used to elicit a response.
SurveysA collection of information through written or verbal questions.
Theta waveA type of brain wave detected by EEG. In the range of 4-7 Hz.
Time domainA way to assess certain signals – how a signal changes over time.
Time spentAn eye tracking metric. The amount of time that an individual, or group, spends looking at a defined area of an image.
TonicA baseline GSR signal that is related to physiological exertion.
TTFFTime to First Fixation. An eye tracking metric. The duration of time between when an individual first encounters a stimuli until they fixate upon a defined point.
ValenceThe emotional experience. Positive valence is akin to feelings of joy, happiness, etc. Negative valence is akin to feelings of sadness, disgust etc.
VRVirtual Reality. A headset-based screen that places the user in a virtual world.
Zygomaticus major A muscle of the face, located around the mouth and associated with smiling.

Have another term that you’d like to add? Get in touch and we’ll update the list.

Want to go beyond terms and become an expert in human behavior research? Get the full picture with our free guide to human behavior, which you can download below.

Human Behavior Pocket Guide Insert