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Influence of Video Stream Quality on Viewers’ Emotional Engagement

By Gawain Morrison

With the hyper-connectivity of the internet and online media in general, viewers’ emotional engagement is a particularly important variable to take into account for TV ad effectiveness. However, the technical quality of the video stream can also affect the viewers’ experience. Buffering and low video quality are still events that potentially trigger negative emotions in viewers.

Therefore, for streaming media and video-on-demand, companies have to take care of the viewers’ experience in order to ensure their brand loyalty. Indeed, brand loyalty clearly impacts direct revenues – up to 60% of their subscriber base annually, which is three to five times more than a traditional Pay TV provider. Subscriber churn not only has implications for revenue generation but also subscriber acquisition costs.

As such, it is imperative that the quality of the viewers’ experience is good - especially in models where long-term commitments are not required. This study investigates the impact that online video quality has on viewing experiences across different delivery methodologies. The viewing experience was measured and its impact on the associated business model was determined. We tested this across three business models: Transactional (Quick TV), Ad-Supported (Free TV) and Subscription (24/TV).

To do this, we placed participants in either high-quality or low-quality viewing experience whilst using skin conductance measurements. Participants were selected to take part on-site in Belfast, UK. Participants watched the content on a 55 inch 4K TV in viewing rooms that met the VQEG standards. We created three brands to remove any previous emotional association with the business models and used the same content across all the brands to nullify the impact of content type on the participants.


Galvanic Skin Response (GSR) allows us to measure a consumer’s emotional engagement in response to a stimulus. This is used to determine the arousal level of the consumer. When using GSR alone, we can identify key moments of engagement recognized by a single spike. We can also look at the overall gradient of skin conductance level known as tonic activity to gain longer-term engagement. The sensors we used are the best in class for measuring emotional engagement (Figure 1). Across GSR data, we were specifically looking at time series analysis. We were investigating the effect of a poor quality experience, specifically the point of buffering in the content. Reviewing participant emotional responses in this way allowed us to look at how emotional engagement is affected over time and the impact per second.

To test their emotional engagement, 134 participants (59 males and 75 females) taken from the Millennial generation were recruited to take part in this experiment. Even if Millennials view four-seven hours of online video a week – nearly twice that of all other age groups – they are the hardest group to keep satisfied and have a short attention span and a low tolerance for poor service.  Understanding Millennials’ psychological processes allow successful streaming media and video-on-demand companies to understand people’s expectations and why people stay away if expectations are not met.

Each participant was exposed to a short sci-fi commons piece which lasted for one minute and 30 seconds, called “Tears of Steel”. It comprised of some action and drama elements. In order to compare the influence of the video quality definition on the facial expression, this film was shown both with a high and low quality. Finally, a buffering disruption was included at 0:43 seconds of the ‘low quality’ video in order to evaluate emotional engagement triggered by this technical disruption compared with their overall engagement.

Figure 1: Galvanic Skin Response device used to identify viewers' experience


At 0:40 seconds, there is a highly dramatic moment with the music and visuals changing. Just after this point, the pre-determined buffering occurs at 0:43 seconds (marked in orange). Comparing the areas of comparative response (Figure 2A and 2B) there is a 19.8% greater emotional impact in high quality than low-quality viewing experience.

Figure 2A and 2B. Comparison of the skin conductance according to the absence (A) or presence (B) of a buffering in the chosen video identifying viewers' experience

In Figure 2A the significant increase in skin conductance regardless of the business model indicates a high level of emotional engagement during that sequence. However, the experience of buffering in Figure 2b reduces this emotional impact, most notably for the subscription model (24/7 TV). The skin conductance results clearly indicate that a low quality experience interrupts engagement and dampens the emotional impact of the contents’ storytelling and immersion.

Figure 3. Impact of video stream quality on viewers' emotional engagement

In Figure 3 we have indicated in green and orange the emotional response ranges for high quality and low quality. When we compare these ranges, we see a 19.8% difference of emotional engagement between high quality and low quality. The secondary bump at 0:46 seconds in the low-quality experience is most likely due to a moment of negative arousal as the participants react to the buffering period.


Viewers were more engaged in the plot and exhibited more skin conductance when watching the same content at a higher bit rate, even without any buffering. Whilst all business models exhibited a more positive response in higher-quality streaming, the subscription to streaming media and video-on-demand companies saw improvements in viewer experience of over 10%.

  • Emotional engagement reduces by 19.8% when disturbing viewing experience.
  • If buffering takes place at a moment of high intensity in a viewing experience, the subsequent engagement responses are dampened as a result of that buffering.
  • Buffering has affected all brands, most notably the subscription (24/7 TV).
  • After a buffering event, the dampening engagement effect on the subsequent viewing experience is ongoing.
  • These results demonstrate the impact that a low-quality experience has on the audience immersion of content no matter the business model.

With the development of video-on-demand and online video streaming, the viewers’ experience has changed from passive to active. Viewers tend to be emotional consumers. Therefore, analyzing their emotional engagement is particularly relevant, notably to ensure good customer experiences for a range of content delivery business models. Nevertheless, video quality can vary widely and can lead to extremely negative viewers’ experiences.

Whilst this phenomenon has been described in many other studies, we have now been able to measure the actual impact on viewership. We can also see how delivering content in higher quality resolutions and bit rates also deters ”casual pirates” who tend to subscribe to streaming media and video-on-demand companies. This experiment shows explicitly that video buffering significantly decreases viewers’ emotional engagement. Using skin conductance measurements, we were able to evaluate how this negative experience not only impacts business models but also helps streaming media and video-on-demand companies to combat video piracy. 

This article was originally published in the Neuromarketing Yearbook. Order your copy today