Experiment building - on online experiments

Notes related to setting up behavioural experiments and such. Experiment design Hardware and timing Experiment building - on timing · on online experiments · on counterbalancing E-Prime notes · PsychoPy notes · Experiment builder notes · Gorilla notes · PsychToolbox notes · OpenSesame notes · DMDX notes

Online experiments, as convenient as they are, means there are many things you can no longer control for - display time, hardware response time, browser details, whether it is a computer or a phone (I have a years-old phone and I would absolutely not trust its timing), headphone quality (there are some tests you can do to get a gauge of this)

Browser

Assume that browsers tend to merge movement into 60Hz intervals - or whatever monitor-limited speed it's drawing at - so negating the effects of any 1000Hz keyboard / mouse / button device you may have.

Also, behaviour and even rendering details may vary between browsers.

Also, multitasking in browsers varies between browsers. Maybe there's a video stream in another tab making things... more varied.

Since it's not something you can control, at all, it's not a good environment for precision timing.

Easy for questionnaire style stuff, though.

Unknown hardware

You do not control the quality of headphones, microphones, webcams, delay in input, delay in display.

Lower quality or more delay is arguably less important than inconsistent quality and inconsistent delays.

All the things you can control for in a lab are almost fundamentally impossible to control elsewhere.