The Virtual Commons

building extensible software for collective action research

Foraging Experiment Configuration

There are a number of configuration parameters you can use to tweak the runtime behavior of the foraging experiment. In order to modify an experimental treatment you will have to perform the following steps:

  1. Make sure your foraging/src/main/resources/configuration directory contains the appropriate server.xml and round*.xml files. This directory must contain at minimum a server.xml file and its referenced round*.xml, e.g., round0.xml, round1.xml and round2.xml. There are samples used from experiments run at Arizona State University and Indiana University stored in foraging/src/main/resources/configuration/asu-experiments and foraging/src/main/resources/configuration/indiana-experiments. If you end up losing or corrupting the configuration files, you can always copy that set of configuration files from one of these directories to start off as a sample by executing something like cp foraging/src/main/resources/configuration/asu-experiments/* foraging/src/main/resources/configuration/.
  2. Modify the round*.xml files as needed to tweak or change any of the parameters listed below.
  3. Modify as necessary according to the Foraging Deployment instructions.
  4. Run ant deploy from the top-level foraging directory where the build.xml file resides - see Foraging Deployment for more information about deployment.
Parameter Name Allowed Values Description
chat-enabled true / false Enables/disables a communication round before the beginning of this round.
chat-duration 0 - N Duration of the communication round, in seconds.
chat-instructions text/html Rudimentary HTML or text to be displayed when the user is given the opportunity to chat.
sanction-type real-time / post-round / none The type of sanctioning allowed. When set to real-time, participants are allowed to sanction each other during the round. When set to post-round, participants may only sanction at the end of the round and are presented with a table allowing them to choose how many tokens to reduce from each other participant. Make sure to also specify the sanction-cost and sanction-penalty parameters (these default to 1:2, respectively, so it costs a participant one token to reduce another participant's tokens by 2).
practice-round true / false Enables/disables the practice round. In the practice round, participants will be able to reset the resource distribution, but do not receive any income from the tokens they collect.
clients-per-group 1 - N If set to a number > 1, participants are placed partitioned into groups consisting of N participants each. Each group has a resource distribution, and all participants in each group share that resource distribution in an open-access setting.
regrowth-rate float between 0 - 1 The regrowth rate is the multiplier / scaling factor used to adjust the probability that the current cell generates a new token. It is multiplied by the neighboring tokens ratio to generate a minimum threshold probability.
max-cell-occupancy integer between 1-N The maximum cell occupancy represents the number of participants that can occupy a given cell. If set to 1, then only one participant can occupy a cell at a time. If set to N, then N participants can all occupy the same cell.
display-group-tokens true / false Enables/disables the group token display that shows the current tokens for all members of the group at the top of the screen.
quiz true / false Enables/disables a quiz for this round, which causes the server to block until all quizzes have been submitted.
quiz-instructions text/html The instructions to be displayed for the quiz, should contain the form and input fields as well. Input fields in the form should named q1, q2, q3, ... qn so that the quiz questions can be correlated with their answers. The answers to the quiz questions should be created in a similar format, i.e., for the given example, there should also be q1, q2, q3, ... qn configuration parameters.
always-explicit true / false Enables / disables whether or not explicit mode is always on.
duration 0 - N Duration of the round, in seconds.
resource-width 0 - N The width of the resource grid.
resource-depth 0 - N The depth of the resource grid (in the 2D of the foraging experiment, this is the height).
private-property true / false Enables / disables single participant per resource grid, typically used for the practice round only.