Updating the BitStream Files

To update BitStream files:

1. Go to the Report > Update BitStream Files menu command.

The update dialog opens .



Figure 1 - Updating the BitStream files

2. Select whether or not you wish to include incomplete responses, then click OK.

A task is sent to the task queue, and the task is run as appropriate.

If you are running a live survey and wish to have the BitStream files updated at regular intervals to add new responses, you can set up a recurrence pattern on the BitStream generation task. You can for example have the files updated twice a week on Mondays and Thursdays at 2 o'clock in the morning.

As the BitStream file creation process will interrogate the SQL database to retrieve the data on the survey, you are recommended to set the task to run during periods when low activity in the survey can be expected, for example late at night.

3. To set the task to repeat at regular intervals, go to the Recurrence tab and click Change .



Figure 2 - The Recurrence Pattern dialog

4. Make the settings as required then click Save.

Note: The times the task is set to run will be "server" time - the time at the server on which your project is running. If you are sitting in a different time zone from the server, you must bear this in mind when deciding when you wish the task to run.

The tab changes to the layout shown in the example below. The next few scheduled occurrences are listed.

Figure 3 - Example of the Recurrence tab with scheduled occurrences

When running a BitStream file generation on a project where BitStream files have already been created, the existing BitStream files will be updated if:

• Responses are added, changed or deleted.
• Questions are added or removed from the survey.
• The type of a question is changed (for example multi -> single).
• Questions or loops are moved into another loop or out of a loop.
• Codes are changed or items are added to or removed from the answer lists of grids, multis and loops.

This ensures that the calculations performed on the BitStream files will be correct with respect to the content of the entire survey database at the time of the last execution of the BitStream generation task.

If you use recoded variables in your survey (see the Forsta Authoring documentation) ensure that the recoded variables are calculated for new responses before the BitStream generation is run. However, you should choose carefully which respondents the variables are to be calculated for. Note that choosing All will mean that recoding will touch all responses in the survey database, and when all responses are updated, the BitStream files must be updated for all respondents as well. You are therefore recommended to use Uncalculated or Only New Respondents if you can . (Read more in the Forsta Authoring documentation).

Figure 4 - The Calculate Variables options