Nomophobia is defined as the fear of being out of mobile phone contact and is considered a modern age phobia introduced to our lives as a byproduct of the interaction between people and mobile information and communication technologies, especially smartphones. This research study sought to contribute to the nomophobia research literature by identifying and describing the dimensions of nomophobia and developing a questionnaire to measure nomophobia. Consequently, this study adopted a two-phase, exploratory sequential mixed methods design. The first phase was a qualitative exploration of nomophobia through semi-structured interviews conducted with nine undergraduate students at a large Midwestern university in the U.S. The qualitative findings from this initial exploration were then developed into a questionnaire measuring nomophobia. In the second phase of the study, the nomophobia questionnaire (NMP-Q) was tested with a large sample of 301 undergraduate students.

As a result of the first, qualitative phase of the study, four dimensions of nomophobia were identified, namely not being able to communicate, losing connectedness, not being able to access information and giving up convenience. Using the findings from this phase, a 20-item NMP-Q was created. The results of the second, quantitative phase showed that the four dimensions were connected to the theoretical construct of nomophobia and that the NMP-Q produced valid and reliable scores.

Utilizing both qualitative and quantitative approaches, this study provided greater insight into nomophobia as a theoretical construct. In addition, the methodology employed in this study - exploratory sequential mixed methods design - offers a guide in the development of new measures to investigate the impact of technology on people's lives.