Recall that Blumenstock was interested in measuring wealth and well-being. But, these traits are not directly in the call records. In other words, these call records are incomplete for this research, a common feature of digital traces that was discussed in detail in Chapter 2. But, it seems likely that the call records probably have some information about wealth and well-being. So, one way of asking Blumenstock’s question could be: is it possible to predict how someone will respond to a survey based on their digital trace data? If so, then by asking a few people we can guess the answers of everyone else.
Kumbuka kwamba Blumenstock ilikuwa na nia ya kupima utajiri na ustawi. Lakini, sifa hizi haziko moja kwa moja kwenye rekodi za simu. Kwa maneno mengine, rekodi hizi za simu hazijakamilika kwa utafiti huu, kipengele cha kawaida cha athari za dijiti ambacho kilijadiliwa kwa kina katika Sura ya 2. Lakini, inaonekana kuwa rekodi za simu labda zina habari fulani kuhusu utajiri na ustawi. Kwa hiyo, njia moja ya kuuliza swali la Blumenstock inaweza kuwa: inawezekana kutabiri jinsi mtu atajibu uchunguzi kulingana na data zao za ufuatiliaji wa digital? Ikiwa ndivyo, basi kwa kuuliza watu wachache tunaweza kukisia majibu ya kila mtu mwingine.