I-GROUP PRESENCE QUESTIONNAIRE: PSYCHOMETRICALLY REVISED ENGLISH VERSION
Mehmet İlker Berkman, Güven Çatak
Abstract
I-group Presence Questionnaire (IPQ), which is used to evaluate the mediated experience of presence -especially for virtual reality applications- is originally developed in German and translated to several other languages. However, there is not any psychometric study for these translations including English version, except the Portuguese and Persian translations. We evaluated English translation of IPQ with 36 participants through 12 VR sessions with an overall of 432 samples. Using a partial least squares based factor analysis approach, the original 14-item set is trimmed into 11-items in order to achieve better psychometric qualities. In addition, a covariance based confirmatory factor analysis is executed to compare models. Several indices, even the conservative Cronbach’s alpha indicated that the subscales of 11-item version are reliable, but not the 14-item version. Eliminated items did not lead to a decrease in scales’ sensitivity to identify different levels of Realism, Spatial Presence and Involvement for different virtual environments. Although we provided evidence to remove the items which are identically worded and inversely coded that are causing measurement error, we suggest researchers to employ the 14-items but report the results for both 14-item version and 11-item version, until the psychometric qualities of IPQ in English is confirmed with a larger sample of participants.