Cellphone data into research

Every time a person uses a cellphone, information is registered and stored digitally. This can be valuable for research into Africa, according to NAI researcher Johan Kiessling. The challenge is to know what you are looking for.

Information from a cellphone is called Call Data Records (CDR) and is a form of “Big Data” which also includes information from internet browsing, credit card payments and other digital activities. In Africa, however, the internet and online payment are not yet very well developed. Mobile phone use, on the other hand, has rapidly grown in recent years. Therefore, CDR has a potential to assist social science on Africa.

“Since every phone is like a transmitter, CDR can show where people are and where they are going. This can facilitate studies on labour migration or people’s movement during conflicts. If CDR had been considered after Ebola broke out, perhaps the spread of the virus could have been tracked earlier by tracing where people went. It also tells us how and when a person pays cellphone charges and thereby indicates the economic status of the owner,” Johan Kiessling continues.

CDR has its limitations
However, there are limitations. CDR never tracks a person, only the phone’s SIM card. In many African countries, several persons often share one cellphone, so even when research shows that 90 per cent of women in Tanzania have access to a phone, this doesn’t mean they own one personally.
It is also difficult to secure samples that are representative.

“CDR only tells us something about people with phones. It is likely that rich people have several phones and it is also likely that their behaviour differs from that of poor people. Thus, the information does not reflect the population at large. Particularly in Africa, many people live beyond the range of CDR and therefore it is tricky to draw general conclusions,” Johan Kiessling notes.

Need for disciplines to cooperate
If CDR is to be relevant for research into Africa, various disciplines need to cooperate. Anthropologists probably discern different things in the information from economists or political scientists, epidemiologists and experts in other fields.

“Many answers lie in Call Data Records, but unless you know to ask the right questions you risk drowning in all the information” Johan Kiessling concludes.

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