Does Length Matter?
Previous research has suggested that optimal video length for online
activities should fall in the 6-9 minute range (Risko et al 2012; Guo et
al 2014). Only one of the videos selected for this class was this short
and the longest video was four times this recommended length. Comments
on length tended to be uncommon in the feedback on each individual video
(Fig 4 ), but the comment that homework assignments generally
were too lengthy and time consuming was in the top 10 response
categories on the end-of-quarter feedback (Fig 7 ). It is
possible that the end-of-quarter surveys are a more accurate reflection
of student perception given their anonymity; however, even in this
format, complaints about length appeared in less than 12% of comments
(n = 29/243).
Homework 3 is an interesting case on this point. It included two videos
that totalled nearly 19 minutes and which were rated lowest among all
videos in terms of academic engagement (Fig 6a ) and emotional
engagement (Fig 6b ) and for which the homework assignments
received more than 5 times the number of complaints as any other
homework. Yet this assignment received no negative, and two positive,
comments about length (Fig 4 ). Both of the homework assignments
that included two videos received fewer complaints about length than
their total run time would predict compared to other videos (Fig
4 ), suggesting that multiple short videos were more palatable to
students than one video of the same total length.
Homework 4 is also an interesting case. This was the longest video
assigned, and was also rather advanced in terms of content and
terminology. This video received the most negative comments about
length, but was on par with or lower than other videos for other
negative comments. Additionally, this video was the second highest rated
in terms of positive comments on the presenter and tied for
third-highest taxon of interest. Consequently, even a long lecture-style
video on a complex topic can be interesting to students if paired with
an engaging speaker and a charismatic organism.