Yes! Viewers are able to speed up or slow down the playback of the interactive video on the Zaption player. Authors are able to prevent viewers from using this option in the Lesson Settings menu.
Not all videos allow speed to be adjusted. For example, users can change the playback speed for videos hosted on YouTube or Zaption, but this may not be available for videos hosted on Kaltura or Vimeo. The different play rates (i.e. .5x-3x) are based on the original video host.
If a viewer watches the lesson at an increased speed, the viewing time will reflect the actual amount of time they spent viewing the video, not the duration of the video. For example, if the student watches a 6 minute long video at 3x speed, a viewing time of 2 minutes will appear in the Analytics.