User testing

Immersion can be measured through objective measuring instruments and subjective measuring instruments:

• Objective measuring instruments mainly try to measure user response, without the user being able to think too much about his / her response. Objective measures within research into VR / 360 ° applications can be very diverse and vary in complexity (eg heartbeat, pupil dilation, time to complete a task, brainwaves).

• Subjective measuring instruments capture a response from the user, whereby the latter can reflect cognitively about his / her answers, which is why these are sometimes also referred to as self-reporting. The best-known forms of subjective measurement instruments are written questionnaires and interviews (zie bijv. Jennett et al., 2008; Bianchi-Berthouze et al., 2006).

Both methods appear to have advantages and disadvantages. The main advantage of objective measurements is that they are less susceptible to self-report bias on behalf of the respondent. The biggest disadvantage of objective measuring instruments, such as heart rate registration, is that it is very difficult to interpret this objective response unambiguously. An increased heart rate may indicate interest and attention, but may also indicate other affective reactions such as anxiety or anger. In eye-tracking, another objective method of measurement, the question arises as to what exactly it means when a respondent focuses his eyes. The interpretation of this is to a certain extent a subjective matter.

The main subjective measuring instrument are surveys, questionnaires or interviews. These measuring instruments are currently the most commonly used instrument, but have two major drawbacks: firstly, full trust in the fair reporting of the respondent (while we know from metaanalyzes that respondents often provide socially desirable answers through surveys) ( Steenkamp et al., 2010). A second major disadvantage of surveys via questionnaires is that the respondent should actually have some notion of what it means to be "immersed" in order to be able to answer questions about this, whereas this is not a necessary condition for objective measuring instruments (Ijsselsteijn et al., 2000).