# Reaction-time comparison checklist: methods and claim sheet

Version 1.0 · 26 September 2026

Canonical paper: https://www.altamens.com/research/reaction-time-comparison-checklist/

Publisher: Altamens, the commercial mental-practice product. AI-assisted methods note and targeted narrative evidence review. No independent human methods review or journal peer review was performed. This is not a validated measurement instrument.

## Scope and provenance

No Altamens user data or participant records were accessed. No human sample, simulated sample, training-effect estimate or new hardware benchmark is reported. Published timing findings are cited, not reproduced. The diagram is schematic; its stages have no measured durations.

Search and inspection date: 26 September 2026. Queries covered “online reaction time timing accuracy browser experiments”, the “timing mega-study”, “realistic precision and accuracy of online experiment platforms”, and “Reimers Stewart presentation response timing HTML5 JavaScript”. Selection favoured accessible primary hardware benchmarks, author-hosted results and the official timing specification. This targeted selection is not a systematic review and makes no completeness claim. Historical benchmark versions cannot establish current browser/device rankings. Marketing norms and unverified correction factors were excluded.

Product source inspected: Edworking/altamens revision `eed1af34c99d6bd9e883e2fe276e9b80fb512d70`, `app/tests/reaction-time/page.tsx`. This identifies a source-code audit, not a public dataset. Source inspection is not external hardware calibration. No game code was changed by this paper.

## Claim-to-source map

| Claim or contribution | Evidence | Boundary |
| --- | --- | --- |
| `performance.now()` supplies a monotonic software timestamp; resolution may be reduced | [W3C High Resolution Time, 1 September 2026 Working Draft](https://www.w3.org/TR/2026/WD-hr-time-3-20260901/) | Not a physical screen-onset measurement; draft status |
| External equipment distinguishes intended events from physical measurement | [Reimers & Stewart, 2015](https://link.springer.com/article/10.3758/s13428-014-0471-1) | Historical tested configurations, not current universal offsets |
| Response-time lag and variability are separate measures | [Bridges et al., 2020, author-hosted Table 3](https://psychopy.org/timing/2020/table3.html) | Table inspected; raw data not reanalysed; no platform ranking inferred |
| Platform performance depends on tested conditions | [Anwyl-Irvine et al., 2021; online 2020](https://link.springer.com/article/10.3758/s13428-020-01501-5) | Historical software versions and declared commercial affiliations |
| Altamens stores a rounded mean of five accepted, millisecond-rounded intervals; early responses retry | Product source revision above | Five trials are not five people; no repeatability estimate |
| Eight-check comparison workflow and blank record | Altamens' proposed synthesis and documentation aid | Not empirically validated; no causal or diagnostic interpretation |

## Using the blank CSV

[Download comparison-record.csv](https://www.altamens.com/research-assets/reaction-time-comparison-checklist/comparison-record.csv).

This file has one row per documentation field and blank columns for two runs. It contains no observed scores. Fill it privately; do not enter names, account IDs or health information. Use “unknown” when a version or condition cannot be recovered. Keep mean, median and fastest-trial results distinct. Record only counts or summary values the test actually provides; do not infer unrecorded early-response counts.

The `comparison_class` field accepts a plain description: `within-setup`, `changed conditions`, or `insufficient information`. These are descriptive categories, not a validity score. A matching setup does not establish reliable improvement or causation. If the setup changes, keep a separate comparison series rather than subtracting a guessed hardware correction.

No analysis code, dependencies or random seed are needed: no statistical analysis was performed. The CSV and article can be inspected directly. The canonical HTML is the citation target; no DOI or preregistration is claimed. Third-party figures or raw datasets are not redistributed, and their original licences remain with their owners.

Suggested citation: Altamens (2026). Before You Compare Reaction-Time Scores: A Measurement Checklist. Methods note, 26 September. https://www.altamens.com/research/reaction-time-comparison-checklist/

For corrections: support@altamens.com, verified on https://www.altamens.com/privacy/ on 26 September 2026. This is the product's support contact, not an independent scientific reviewer. No individual scientist or independent reviewer is represented by the publisher label.