Database Schema

The experimenter e-mail address. This is used as a predefined template value for the instructions. It is also used as the destination for backups of the database. Initialises to foo@example.com.

The experimenter password. Note: this is stored as cleartext, so it is not really a hash. Initialises to xyzzy.

Unique identifier.

Bit-field on whether the email and hash have been set by the user. Contains 0x01 if the e-mail has been set, 0x02 for the password.

When this was created (epoch).

The game.

Unique identifier.

The participant.

The round number (starting at zero).

The session.

A text (space-separated) list of rational numbers of the strategy mixture ordered from the top if a row-playing role (i.e., player.role) or left if a column-player.

Number of entries in choice.strats. This obviously equals the number of strategies available to the participant in that game, given the player role.

The experiment is currently accepting (or did accept) auto-added participants.

Preserve the experiment.autoadd state during and after the experiment start. This is useful for rolling experiments so as not to have a break between starting the experiment and re-enabling captive mode.

If not an empty string, a Mechanical Turk access key. This and experiment.awssecretkey must be set in order to enable a Mechanical Turk experiment.

How to convert a Mechanical Turk participant's final score (tickets) into real currency, if applicable.

Description of this Mechanical Turk experiment, if applicable.

If not an empty string, set to an error from a preceeding Mechanical Turk “start new HIT” operation that failed.

Keywords (comma-separated) of this Mechanical Turk experiment, if applicable.

If non-empty and applicable, the locale to request (country code) for Mechanical Turk participants.

What to call this Mechanical Turk experiment, if applicable.

The base reward to give to Mechanical Turk participants, if applicable.

Whether to use the Mechanical Turk sandbox in all enquiries, if applicable.

If not an empty string, a Mechanical Turk secret key. This and experiment.awsaccesskey must be set in order to enable a Mechanical Turk experiment.

If <=0 and applicable, the number of HITs for each Mechanical Turk participant.

How many Mechanical Turk workers to request, if applicable.

If <=0 and applicable, the percent (out of 100) of approved HITs for each Mechanical Turk participant.

Bit-field. Contains 0x01 if the history is not to be transmitted to participants, 0x02 if games and rows shouldn't be randomised prior to display, and 0x04 to show participants the relative count of rounds—relative to when they started to play.

A JSON file that provides a “fake” history prepended to the actual experiment history. This is only shown to users through the browser interface.

HIT (Mechanical Turk) identifier given by the Mechanical Turk server for an mturk experiment. Otherwise, an empty string.

Unique identifier.

The instructions shown to participants. This must contain valid HTML5. It may contain @@gamelab-admin-email@@, which is filled in with the experimenter's configured e-mail address; @@gamelab-games@@ for the number of games; @@gamelab-rounds@@ for the number of rounds; and @@gamelab-round-time@@, a decimal number of the number of hours per round.

Set when the experiment begins (i.e., when experiment.state <0), this is the URL given to players in their initial e-mail for when they log in. This is suffixed by “?ident=EMAIL&password=PASSWORD”.

Human-readable amount awarded in lottery, e.g., 10 000 SEK. If set to the empty string, there's no lottery.

The number of minutes per experiment.round. Minimum of one.

The maximum number of participants per player role at any given time. If zero, the number of participants is unbound.

The number of rounds playable by each participant. If zero, participants will play until the end of the experiment. If <0, participants will not be allowed to play more than the given number of rounds within the experiment.

If non-zero, new participants are not directly assigned a join round and must use the lobby facility. There, they will be asked questions and cannot proceed until all questions have been answered. See questionnaire.

The current round of the experiment, or -1 if the rounds have not begun incrementing. This will be set to experiment.rounds when the experiment concludes.

If round is non-negative, then the epoch when the round was incremented. Otherwise, this is zero.

If roundpct is non-zero, this is the “grace time” (in minutes) before which the round will automatically advance giving the percentage.

If <0, this represents the fraction of participants per player role who play all games and determine that the round automatically advances. In other words, if set to 0.5 (50%), then from both player roles, if 50% or more participants have played all games, the round advances in advance of the set round termination time.

If specified when configuring the experiment, a daemon will be started that periodically checks to see if the round has advanced. Its process identifier is stored in this field. Otherwise, this is zero.

The number of rounds that will be played. Minimum of one.

Epoch when the experiment when the first round of the experiment begins.

The running state of the experiment, being either 0, for new (still in the configuration stage); 1, for started (participants can log in, though the experiment itself may not be accepting plays yet); 2, where the experiment has expired, but the winner has not been chosen by the experimenter; or 3, where the experiment has expired and the winner has been chosen.

When the experiment finishes (i.e., when experiment.state is set to 2), this is filled in with the total number of lottery tickets (the player.finalscore) awarded to all participants.

Unique identifier.

The name of the experiment. This is shown only to the admin.

Number of strategies for row player.

Number of strategies for column player.

A list of space-separated payoffs from the top-left to the bottom-right of the payoff matrix, ordered row-player payoff, column-player payoff.

The number of games this participant has played, i.e., the count of choice rows.

Unique identifier.

Participant identifier.

The round number (starting at zero).

The player's aggregate payoff (as a rational number) computing by adding the previous round's aggregate payoff to the current lottery.curpayoff.

The value of lottery.aggrpayoff represented as a natural number of tickets.

The participant's current payoff (as a rational number) computing by accumulating her payoff.payoff for all games in the experiment. This is set to 0/1 if the participant has not played all games.

Unique identifier.

The participant owning the lottery.

The round number (starting at zero) for which this lottery was computed.

For the row player, the average strategy mixture of the current round. Strategy mixtures are only considered for choice rows where the player played all games for the round, so this will be a set of zeroes if no participant completed all games. This is recorded as a space-separated sequence of rational numbers, one per strategy.

Like past.currentsp1 but for the column player role.

Game being referenced.

Unique identifier.

The total number of plays that were submitted (over all games) in this round if and only if the participant submitted for all games in that round.

The round starting at zero.

The accumulated count of rounds not skipping, i.e., the count of zero-valued skip rounds.

If zero row or column-player participants played all games, this is set to 1, else it is 0 (sufficient players played).

Game identifier.

Unique identifier.

A rational number of the payoff.

Participant identifier.

The round number (starting at zero).

If the questionnaire facility has been enabled (via experiment.questionnaire), this is non-zero if the questionnaire has been answered.

If the participant joined from Mechanical Turk, the assignment identifier. Otherwise set to the empty string.

Player was auto-added (i.e., auto-added herself). These participants are never e-mailed.

Player e-mail address or identifier, in the event of a captive participant. This is unique in the set of all participants.

Whether a participant is allowed to login during an experiment.

The minimum of the slot of the participant's tickets among all participants' tickets. For example, given 100 participants with roughly 10 tickets each, this might be 543 to indicate that slot 543 to 543 plus player.finalscore are this participant's slots in the lottery. Mechanical Turk players are not included in this computation, so this value is not meaningful for them.

Set to the accumulated payoffs from lottery.aggrpayoff rounded up to the nearest integer. Mechanical Turk players are not included in this computation, so this value is not meaningful for them.

The participant's password set when the experiment is started (i.e., when experiment.state is <0) or when reset, or when a captive participant registeres. Note: this is stored in the clear: it is not a hash!

If the participant joined from Mechanical Turk, the HIT identifier. Otherwise set to the empty string.

Unique identifier.

Whether the participant should be shown instructions when she logs in (versus being taken directly to the game-play tab).

The round when the participant joined (i.e., started playing) the experiment. This is set to zero when participants join at the outset. If -1, the participant exists, but has not yet started participating in the experiment.

Whether the Mechanical Turk participant, if applicable, has indicated that they've finished the experiment. Note that this is unprotected and can be set at any time: it is only used to display a message to report to the Mechanical Turk server.

The player role (0 for row player, 1 for column player) set when experiment.state is <0 or when the participant joins.

A cryptographically random number <0 given to the participant when created. This is used for many purposes, one of which being the bonus identifier for Mechanical Turk participants.

The state of a participant can be 0, meaning the participant is newly-added and has no password; 1 when the participant has been mailed her password; 2, the participant has logged in; and 3, an error occured when the password e-mail was attempted.

A number from zero that indicates the number of time the player columns have been updated. This is used to make the object cachable.

The epoch time when the row is created.

Unique identifier.

Participant.

The question number starting at zero.

The number of tries, correct or not. This is zero only in the race after initially creating the row and noting an attempt. It should not be used and will be removed.

Magic random cookie for each session.

Epoch when session was created.

Unique identifier.

Participant identifier, if not NULL. Otherwise, this is the admin logged in.

Browser-reported user agent.

The e-mail address used as the “From” address in all communication from the server to participants in the experimenter. It is usually the same as the experimenter email set in admin, but may be set as a standard “No-Reply”. (This is discouraged, as your participants should be able to reply to you if things go wrong.)

Unique identifier.

Whether these entries have been set.

The SMTP username's password (used for logging in). Note that this is stored in cleartext, so make sure that your password isn't used elsewhere.

The SMTP server in smtp://server:port format.

The SMTP server username (used for logging in).

Unique identifier.

Participant.

The random number modulo the total number of tickts used for this winning draw. In other words, this is the winning lottery ticket.

Boolean value as to whether the player is a winner. If this is false, then the winner.winrank and winner.rnum columns are undefined.

If the player is a winner, the rank (first, second, third draw...) of their winning.