The process of data collection itself varies slightly between teams. Each GEM country is required to find a minimum of 2,000 participants to complete the survey, the method by which they identify these participants is largely dictated by the percentage coverage of the landline telephone network. 

Where landline coverage is greater than 85% of all households, then the National Teams are permitted to use a landline-based survey outreach to generate a suitable list of participants to contact. For those countries where landline telephone coverage is not as wide-spread, this approach is less appropriate so face-to-face interview techniques and/or the use of mobile phones are also used.