5.4 Automatically Generated Variables

The CBA ItemBuilder runtime will create some selected variables automatically:

  • reactionTime: Time (in milliseconds) between the start of the task execution and the first user interaction.
  • execTime: Time in (milliseconds) since the start of this task execution.
  • nbInteractions: Number of user interactions since start of the current task execution.

Deployment software for CBA ItemBuilder tasks (see chapter 7) can use identical tasks multiple times and can allow to re-visit tasks. For that purpose, the runtime also computes the cumulative variables:

  • reactionTimeTotal: Accumulated time (in milliseconds) between the start of the task execution and the first user interactions in previous executions of the task (excluding the last execution, that can be found in the variable reactionTime).
  • execTimeTotal: Accumulated time (in milliseconds) in previous executions of the task (excluding the last execution, that can be found in the variable execTime).
  • nbInteractionsTotal: Accumulated number of user interactions in previous executions of the task (excluding the last execution, that can be found in the variable nbInteractions).

5.4.1 Scoring Complete Tasks with Weights

This scoring is included in the CBA ItemBuilder to maintain compatibility with old items. It is considered outdated, as it only allows to derive one score per tasks.

If only dichotomous scoring is required for the complete Task, the CBA ItemBuilder implemented a simple approach.

  • MinHits: For each Task can be defined, how many Hit-conditions must be fulfilled, that the task is scored as True.
  • Weight: Each Hit-/ and Miss-conditions is assigned to a Weight.
  • Class: Each Hit-/ and Miss-conditions is assigned to a Class and to each Class either Hit-/ and Miss-conditions are assigned.

Each task provides the following results:

  • result: Overall result (\(1\) if the at least the number of hits is active that is defined as the property MinHits, \(0\) otherwise).
  • nb_Hits: Number of (active) hits.
  • Hit_weight: Total weight of hits.
  • nb_Misses: Number of (active) misses.
  • Miss_weight: Total weight of misses.
  • credit_Class: Name of the Class with the highest value. The value is computed as the sum of weight for all active Hits (in classes with Hits) or all active Misses (in classes with Misses).
  • credit_weight: Weight of the class with the highest class weight.