arena

Experiments

arena makes a trial run as a multiplayer trial and lists which multiplayer spaces (participants strip, data, log, chat) are visible while it runs. It does two things on a trial row:

1. Makes the trial multiplayer. Any non-empty value makes the trial wait for the other participants: nobody starts the trial until everyone has reached it. On the last trial, the end of the experiment waits the same way.
2. Lists which multiplayer spaces are on screen during the trial. The tokens in the cell turn the participants strip, the data space, the log space and the chat panel on.

The arena value is not a room or session name. Participants are grouped by the multiplayer session they joined, not by this value. If a participant did not arrive through a multiplayer session, arena has no effect for them.

Syntax

List the spaces you want on screen during the trial, separated by ;:

arena
participants;data;chat

Any non-empty value already makes the trial multiplayer; the tokens only decide what participants see. Write them in lowercase, matching is case-sensitive. The recognized tokens are listed under Options.

Options

Value / token	Effect
empty (or column absent)	Trial is single-player; the multiplayer spaces are hidden for this trial
any non-empty value	Trial is a multiplayer trial: synchronized start, and the response is shared with the other participants
setup	Shows the spaces configured in the project’s arena settings: the personas strip when the settings put participants in the center space, plus data, log or chat depending on the left and right space settings
participants	Shows the personas strip, when the project’s arena settings put participants in the center space
data	Shows the data space with the other players’ responses
log	Shows the log space; suppressed if data is also shown
chat	Shows the chat panel during the trial. The token must be followed by a space, a ;, or the end of the cell, so chat_before on its own does NOT show the in-trial chat
chat_before	Before this trial starts, participants get a chat screen with an “I am ready” button
chat_after	After this trial ends, participants get a chat screen with an “I am ready” button before moving on to the next trial

Defaults & missing values

Leave the cell blank, or leave the column out of the file, and the row is an ordinary single-player trial: it starts as soon as the previous one finishes, no multiplayer spaces are shown, and the response is not shared with anyone else.

Each row is read on its own, so a trial file can freely mix multiplayer rows and single-player rows.

Works with

• arena_sequence, arena_advance, arena_responses: these only do anything on rows that have an arena value. Without arena the trial is single-player and they are ignored.
• Shared with everyone: arena travels to all participants together with arena_sequence, arena_advance, arena_responses, type, stim1, stimFormat and responseOptions, so everyone in the arena runs the trial the same way.
• Click responses: on a trial whose arena includes data (or setup with a data space configured), other participants’ clicks are drawn as markers on the stimulus.
• Countdown wording: the message shown while waiting says responses will be visible when arena contains participants, data or log, except on clicks trials.
• participants beyond the trial itself: the same token also decides whether the personas strip is shown on the chat-after screen and after the webcam photo step.
• Results: multiplayer trials are saved like any other trial; the response is additionally shared with the other participants while the trial runs.
• Chat before plus manual advance: when the previous trial used arena_advance set to manual and the next trial has chat_before, the ready button leads straight into the chat screen.

Examples

Trial that starts synchronized and shows the personas strip plus everyone’s responses in the data space:

type	stim1	stimFormat	responseOptions	arena
test	Which option do you choose?	word	A;B;C	participants;data

Trial with a group chat visible during the trial and a chat round before it starts:

type	stim1	stimFormat	arena
test	discussion_image	.png	participants;chat;chat_before

Trial that defers everything to the researcher’s arena settings:

type	stim1	stimFormat	arena
test	word_stimulus	word	setup

Tips & gotchas

Caution

chat_before on its own does not show the in-trial chat panel. It marks the trial as multiplayer and adds the pre-trial chat screen, but the panel alongside the stimulus only appears if you also list chat.

• log loses to data: if both tokens are present, only the data space is shown.
• Solo fallback: if the multiplayer session is not ready when a participant arrives, they see an alert and continue on their own. Their trials no longer wait for anybody and their responses are not shared, but the arena spaces can still be toggled on arena rows, so they may see an empty arena area.