Only perfectly aligned data results in proper statistics and analytic results.
In most cases, during analysis, you will discover that your Events need to be optimized for better results. This means that you need to scrutinize your data and make adjustments here and there to eliminated inconsistencies, coding errors etc.
INTERACT offers a bundle of routines and commands to make the best out of your data, without the need to do it all by hand.
Examples for such situations are:
oFill Gaps - If you only coded what was of interest, your data might contain gaps (not coded sequences) per Class. Some statistics provide better results for exhaustive data.
oConvert Intervals into Events - If you have data that was collected in fixed intervals, you can turn repetitive Codes - that last for more than one interval in a row - into a single, coherent Event for that Code.
oConvert Repetitive Markers into Events - If you have coded various repetitive activities with a simple Marker for Frequency counts (e.g. placed a marker for every time a dog says "woof"), but discover during analysis that it would be good to have those activities converted into Events with duration whenever die repetition took place within a specific interval.
E.g. turn "woof" - "woof" - "woof" into an Event labeled "Barking" .
oMerge Repetitive Events - If you have observed many rather short behaviors, but figure out that those activities actually belong to a more generic, longer lasting Event, whenever they occur within a specific time frame. E.g. turn "chewing" .... "chewing" ... "Chewing" ... "chewing" into an Event named "food intake", whenever the chewing was observed within 30 seconds and the pauses in-between should be ignored.
oConsolidate Overlapping Events - Multiple subjects coded in a single DataSet (using lexical chains and a subject code per line) results in overlapping behaviors, because multiple subjects can perform the same behavior at the same time.
In statistics, these overlapping times are all counted for per Event holding that particular Code.
To get the consolidated duration of this behavior (for example 'Playing time' in a Class named 'Activity') without the overlaps - thus independent of the subject, use the Merge successive Events routine.
oConsolidate duplicate Intervals - When Coding the same fix intervals in multiple sessions, using multiple data files, the merged version of these observations hold duplicate intervals that might falsify statistics.
Event Transformation Routines
INTERACT offers the following transformation routines, to help you with this:
 | Adjust Times to Video Frames - All time information is stored as a 100 Nanosecond value to be as accurate as possible. For videos that are recorded at 25 fps (frames per second) this is fairly easy because one frame = 40 milliseconds. For videos recorded at 29.97 fps, the timing is never that clean (1 frame = 33,3667 milliseconds) |
When logging time information INTERACT stores a time value corresponding to an multiplication of a frame duration. Due to latencies caused by the video (codec), using videos with different fps, or other reasons, your file may contain time information that is not perfectly matching the current frames per seconds value of the file.
When displaying your time information in the default Timecode format - showing frames for the last two digits, you cannot see this.
Duration calculation in the statistics is always based on the whole frames you see, so usually, it is not a big deal.
If you make use of routines like the State-Space-Grid or the Pattern Segmentation, the issue might becomes apparent, though.
These routines work with the millisecond information instead of the frames, which means that even if your time information looks perfect to you on Frame-level, there might be tiny gaps and overlaps on the millisecond level.
For gaps, the State-Space-Grid will show a lot of tiny circles in the bottom left corner (or the first column or the bottom row). Dialing the option Show empty codings removes these 'errors'.
When using the Create coding patterns command, tiny overlaps will result in many very small Events (often just a single frame) that will falsify the frequencies.
To eliminate those hidden 'errors' one mouse click is sufficient:
▪Click Transform - Time Values - Align 
to take care of any discrepancies.
All start time and offset times are correctly rounded to a multiplication of a frame duration based on the current FPS value of your data file.
| TIP: | If you temporarily switch to a time format that shows a millisecond value, you can see that the last 3 digits now show a repeating regular value. For example, at 25 fps, you see only these values as the last 3 digits: .040, .080, .120, .160, .200, .240, etc. |
| Verify start time and Offset values - This simple check verifies if all start times are prior to their offsets is performed automatically the moment you open the Timeline Chart. |
| Make data exhaustive - Remove overlaps between Codes per Class using the command Transform - Events - Optimize  > Add missing Codes (make exhaustive). |
| Make data exclusive - Fill gaps between Codes within a Class using the command Transform - Events - Optimize > Remove overlaps (make exclusive). |
| Merge Successive Events - Repetitive Codes can be merged into a single, ongoing Event with the command Transform - Events - Merge  . For details, read merge multiple successive Events. |
| Consolidate Overlapping Events - To consolidate the duration for overlapping behavior, independent of the subject, use the command Transform - Events - Merge . New Events are created that cover the time where at least one subject was performing the selected behavior. |
| Consolidate Identical Intervals - To 'melt' multiple Events with identical start time and Offset into a single event, consolidating all given Codes, use the command Transform - Events - Consolidate Events  .Different Codes for the same interval are never overwritten, so if within the same Class a different Code was coded for that Event, both Events are kept. |