If you mainly want to code or evaluate fixed periods (Intervals) just before and after a certain key-event, INTERACT offers a very powerful command:
Statistics on all intervals of a given Code
You code only the key-Events as they appear (for example 'Imitative periods' like used in the example Create Pre- and Post Events) and let INTERACT create the Events that cover the surrounding intervals:
▪Code your key-Events with just a single Code.
| TIP: | Make sure that there is another Code to mark the beginning of the observation, if your first key Event is NOT the actual start point. This saves you from identifying the exact preceding and succeeding time-spans around your key-events manually. |
▪Run the command Restructure - Add - Pre and Post Events 
, like described in Create Pre- and Post Events.
Note: If you already did code all video material, you can also use this command to concentrate on these specific time spans around a certain key-event during analysis. See Statistics on Pre- and Post- Intervals.
Data Collection per Interval
Depending on your needs, you can now either use the automatically generated Events as a whole, or use them to easily control your video and add new Events for only these periods:
▪Open the Code definitions that contain the Codes you need for logging the behavioral details that occur during those sequences.
Now you can use one of the following methods to collect your data:
 | Log Events per Selected Period - This method describes how you create new, mutually-exclusive-Events within the selected interval. It is like an Event-based coding session, during which you only observe one Pre- or Post-Event at the time: |
▪Make sure your current Codes are mutually exclusive.
▪Select the Coding Mode Standard (ad hoc).
▪Click 
to start your observations.
▪Double click the start time of one of the just created Pre- or Post-Events to position the video at the start of your first sequence.
▪Log the Code that matches the situation at the start of the selected period.
A new Event with the selected Code and an start time that matches the start time of your selected interval, is created.
▪Re-Select the Pre- or Post-Event you want to observe.
▪Reduce the play speed if required.
▪Press F12 or click Play Selected 
to review the current selection.
▪Log the Events with your Codes, as they appear.
As long as you do not pause the video manually, INTERACT automatically pauses the video at the end of the selected interval Event.
When the video pauses at the end of the selected interval, the last code is still 'open':
▪To close the last open code, click that Code again.
| Assign Codes to Selected Period - If only want to enter over-all information for the automatically generated sequences, without further splitting them into separate Events, that is easy. You can enter Codes that describe the predefined intervals, surrounding your key Events, using the Time sampling method: |
▪Open the Code definition file that holds the Codes to label your intervals.
▪Make sure that all Codes that can be assigned to the same Event are mapped to a different Class.
▪Select the Coding Mode Refine existing Events.
▪Double-click the first Interval to review the corresponding part in the video.
▪Enter the Codes as required.
▪Replay the sequence as often as needed.
▪Proceed to the next interval and continue as before
| Create Intervals per Selected Period - It is also possible to split the selected Pre- or Post-Event in even smaller intervals and enter your Codes using the Time sampling method: |
▪Select the Coding Mode Refine existing Events.
▪Make sure that all Codes that can be assigned to the same Event are mapped to a different Class.
▪Select the first Pre- or Post-Event.
▪Click Restructure - Split - Time Split 
(For details, read Create Predefined Intervals)
▪Enter the length of your intervals and confirm
▪Double click the first Interval and enter the Codes as required.
▪Press F12 or click Play Selected to review the current sequence as often as needed.
Data Analysis
| Analyze what happened during those periods - If you have coded all behaviors as they occurred, but now want the statistics on only those surrounding intervals, no problem: |
▪Make use of the Trim on Code filter, based on the automatically created Pre- and Post Events.