Changes between Initial Version and Version 1 of BossaReference

Timestamp:

Feb 9, 2008, 2:24:17 PM (16 years ago)

Author:

davea

Comment:

--

BossaReference

@@ +1 @@
+= Bossa reference manual =
+== Abstractions ==
+
+A Bossa project has one or more ''skill apps''.
+A skill app has a dynamic set of ''skill tasks''.
+Each one has an associated set of arguments describing its parameters or input files.
+Each skill task has a set of ''task instances''.
+Each one represents a copy of the task, either in progress or completed.
+Each instance is assigned either to a user or to a team.
+
+Skill apps are classified as:
+
+ * Online: the task is performed by a single user, sequentially, in a web browser.
+ * Offline: the task is not online, e.g. because it's potentially handled by a group of users, or requires other asynchronous activity.
+
+An app has an associated URL
+identifying a script that takes an task ID argument and displays the task instance.
+The task may consist either of a single web page or a sequence of web pages.
+In either case the last page in the sequence, when done, should call Bossa API
+functions to record the completion of the task, and perhaps display another task.
+
+Skill apps are either:
+
+ * Individually validated: the app has a server-side program that examines a completed instance and decides if it's valid.
+ * Group validated: the app has a server-side program that examines a group of instances, sees if there's a consensus, and if so constructs a ''canonical result'' and marks the instances as valid or invalid.
+
+A project can configure:
+
+ * A maximum number of outstanding offline tasks per user or group
+ * A maximum number of tasks per day issued per user or group
+
+== Volunteer characteristics ==
+
+For each skill app and each user,
+Bossa maintains ''skill estimate'', an estimate of the user's skill at that task.
+This is maintained in the user's project-specific XML document.
+Normally it's a single number in [0..1], and it's initially zero.
+
+The skill estimated can be computed in any of several ways:
+
+ * The results of  the user's interaction with a Bolt course associated with the skill app.
+ * The user's performance on "calibration tasks" mixed into the stream.
+ * The fraction of the user's results classified as invalid by redundancy.
+
+Skill estimates are used for two purposes:
+
+ * To decide whether to give tasks to a user;
+ * To decide how many redundant instances of a given task are needed.
+
+== Implementation ==
+
+To get work, a user goes to a particular Bossa-supplied page.
+There he sees a list of skill apps for which tasks are available
+and for which he is qualified,
+and links to courses for other apps.
+Online and offline apps are listed separately.
+Each app has an estimate of the time or other resources required to complete the task.
+
+Selecting an online app invokes the Bossa ''scheduler'' script,
+which selects a task instance suitable for the user,
+and redirects to its instance URL.
+
+Selecting an offline app invokes the Bossa scheduler,
+which selects a task and redirects to its instance-start URL.
+
+Team administrators are provided with an interface for getting
+offline tasks for the team.
+The scheduler allows a team to get instances only for apps
+for which some team member has the required skill.
+
+Users and teams are provided with an interface for seeing
+a list of pending offline tasks.
+They can indicate that one of them is completed;
+this takes them to the instance-complete URL for that task.
+
+== Integration with BOINC ==
+
+Some offline tasks may involve computation done through BOINC;
+i.e. if the task is assigned to a team, the computation is queued
+in the project's BOINC server and dispatched to members of the team.
+(Or if the task is assigned to a user with many computers,
+those computers are used).