Limitations
Although participants were randomly allocated to the study groups, there were between-groups differences respecting some of the demographic characteristics of participants. Moreover, the non-normal distribution of some study variables necessitated the use of non-parametric methods for data analysis.In addition, the inability to send a file (such as a video) with a size higher than 100 MB was one of the challenges of using WhatsApp. Also, due to the virtual nature of the intervention and the unwillingness of the participants to make a video call, it was not possible for the researcher to observe the participants and it was only possible to receive verbal and textual feedback. But the ability to send text messages on WhatsApp can be considered as an advantage. Because some participants could express their opinions more easily.