Peer-reviewedEye-tracking + online experimentsN=1,600+

How people's attention and decisions change when they know someone else can see what they are doing.

A question with no established way to be measured. I built the measure, then extended it in three directions: how much information is on screen, how beliefs about another person bias decisions, and whether users can judge their own performance.

Role: Mixed-methods UX Researcher Org: Brain, Attention & Reality Lab, UBC Span: Sep 2019 – Aug 2025 Methods: Eye-tracking, online experiments, mixed-effects modelling Outcome: A validated measure where none existed, and three findings on what moves user decisions

The question

People rarely use a product unobserved. Activity is visible to teammates, managers, whoever shares the document - and the moment someone knows they can be seen, their behaviour changes. That makes attention serve two functions: the eyes gather information, and they also give it away.

No established method existed to measure how behaviour changes as we balance these functions, so I built one. I paired users. The first navigated a display and selected a target while their gaze was recorded, sometimes trying to help their partner find it, sometimes trying to hide it. The second then watched that gaze, navigated the same display, and guessed the choice. That gives two measures from one task: what the first user gave away while trying to do their own job, and how the second user read it.

Each study below varies one part of that exchange. Each was randomized, within-user, and modelled with mixed-effects regression. Most ran in the lab and were rebuilt in Python to run online at roughly ten times the sample - 100K+ observations per study. What follows is a sample of six years of self-managed research: 10+ studies, N=1,600+, and $215K in competitive funding, delivered on time and budget.

Display complexity degrades attention management

Question. Can users balance their attentional signals in visually complex computer displays?

Design. Manipulated the display's visual complexity and the task's difficulty (display navigation while self-monitoring attention); tracked search accuracy and eye movements. n=42.

Result. Task success did not decay linearly but collapsed past a threshold. This forced users to make trade-offs between the quality of their decisions and the quality of their attentional signals. Modelling identified these thresholds and their consequences. (Report under review.)

For a product team. Density has a cliff, not a slope. Locating where it sits on your own surface turns "reduce clutter" from a heuristic into a criterion a design review can hold a decision to.

Bar chart: search accuracy falls from 82% at low display complexity to 66% at moderate and 20% at high, against a chance floor of about 11%. 100% 50% 0% 82% 66% 20% chance Low Moderate High Display complexity Search accuracy
Search accuracy by display complexity. Dashed line is chance (1 in 9); error bars are SE. Schematic.

People act on trust more than truth

Question. How much are user decisions biased by another person's attention, and does it depend on whether the user trusts that person?

Design. Modelled users' choices against the strength of another person's attention nudging them to a given choice. Then manipulated whether the user trusted the attentional nudges. n=157, replicated at n=360.

Result. User trust moved decisions more than the nudges themselves - about 30 percentage points from framing alone. High trust followed the cue; low trust discounted it. (Attention, Perception & Psychophysics, 2025.)

For a product team. Credibility signals, source badges, and ranking position can move a decision more than the content they label. Most products never measure that effect, and it is not uniform across user segments.

Line chart: as a cue toward an element strengthens, high-trust users rise from about 15% to 90% probability of selecting it, while low-trust users rise only from about 13% to 25%. 90% 75% 50% 25% 10% high trust follows the cue low trust discounts the cue Strength of the cue toward that element Probability of selecting a display element
Model fit on a logit scale, labelled as probability. Bands are model uncertainty. Schematic.

User confidence is not always a valid measure

Question. Can a user's self-reported confidence in their attention-management ability be trusted?

Design. Collected a confidence rating after every task and tested it against users' actual performance - whether they successfully communicated with their partner - comparing instances where users did and did not know their behaviour was being shared. Eye-tracking n=40 with telemetry n=326.

Result. Confidence tracked performance when users knew they could be seen by their partner, but barely tracked performance when they thought they were not being observed. When users weren't managing their signals, their confidence had nothing to track, so their self-reports were inaccurate. (Journal of Experimental Psychology: General, 2026.)

For a product team. Self-reported confidence is worth instrumenting where users can see the consequences of what they did, and misleading where they cannot. That tells you which surveys and satisfaction scores to trust before you build a metric on one.

Line chart: when users knew they could be seen, higher self-reported confidence predicted that their partner guessed correctly, rising from about 20% to 56%. When users thought they were acting privately, confidence barely predicted performance, rising only from about 26% to 31%. 50% 25% 10% seen by others confidence tracks success acting privately confidence says little How confident the user felt Partner guessed correctly
Model fit on a logit scale, labelled as probability. Dashed line is chance (1 in 9); bands are model uncertainty. Schematic.

Methodology

Program
10+ end-to-end studies, 2019 – 2025, N=1,600+
Design
Randomized, within-user; a paired search-and-signal task built and validated from scratch
Lab
Binocular and mobile eye-tracking, in-person moderated sessions
Scale
Task rebuilt in Python for online delivery; telemetry at roughly 10× the lab sample, 100K+ observations per study
Analysis
Mixed-effects regression; power analysis to right-size samples; reproducible R and Python pipelines under version control
Funding
$215K+ competitive, including NSERC CGS-D and CGS-M

Research that earns adoption

Six years of experiments demonstrated that how a user reads a screen is not a property of the screen. It moves with what they trust, who can see them, and how much information is on it. Adoption is decided in that gap, and that gap can be measured and reduced. The CheckingIn case study is the same problem from the applied side: HR leaders read the dashboard perfectly well and still did not know what to act on, so the interface worked and the product did not.

I apply research to this gap in two ways. First, choosing the approach fit to the question, decision, and constraints, including a willingness to rule out an unhelpful study. Second, building a measure from nothing. Not all research questions arrive with an established measurement approach. I state in advance what would prove hypotheses wrong, validate methods and data before trusting a result, and build the infrastructure that keeps it standing at speed: reproducible pipelines, documentation, collaborative or version-controlled workflows I invite the team into, and AI-assisted qualitative coding with researcher oversight.

Papers and code

Published from this program

Gerlofs, D. J., Roberts, K. H., Anderson, N. C., & Kingstone, A. (2022). Eye spy: Gaze communication and deception during hide-and-seek. Cognition, 227, 105209.

Gerlofs, D. J., Roberts, K. H., & Kingstone, A. (2025). Perceived intent drives gaze interpretation. Attention, Perception, & Psychophysics, 87, 2323–2331.

Gerlofs, D. J., & Kingstone, A. (2026). Metacognition and the dual function of social gaze. Journal of Experimental Psychology: General, 155(8), 1967.

Gerlofs, D. J., et al. Visual complexity and search performance. Under review.