Methods and apparatus to detect user attentiveness to handheld computing devices

A portable device comprising:

• memory;
• computer readable instructions;
• and
• processor circuitry to execute the computer readable instructions to at least:
• download an exposure measurement application from a first server via a network;
• and
• execute the exposure measurement application to:
• identify a change of the portable device from a first starting spatial condition to a first ending spatial condition based on a signal generated by a sensor of the portable device;
• store a plurality of spatial condition changes associated with likelihoods indicative of user attentiveness, a first subset of the spatial condition changes being associated with corresponding engagement likelihoods representing how likely respective ones of the first subset of the spatial condition changes correspond to a user beginning to pay attention to a presentation on the portable device;
• generate user attentiveness data based on whether the plurality of spatial condition changes includes a first spatial condition change having the first starting spatial condition and the first ending spatial condition of the identified change;
• and
• cause the user attentiveness data to be transmitted via the network to at least one of the first server or a second server.

A portable device comprising:

• memory;
• computer readable instructions;
• and
• processor circuitry to execute the computer readable instructions to at least:
• download an exposure measurement application from a first server via a network;
• and
• execute the exposure measurement application to:
• identify a change of the portable device from a first starting spatial condition to a first ending spatial condition, the first starting spatial condition and the first ending spatial condition being angular orientations of the portable device relative to a reference;
• store a plurality of spatial condition changes associated with likelihoods indicative of user attentiveness to a presentation on the portable device;
• generate user attentiveness data based on whether the plurality of spatial condition changes includes a first spatial condition change having the first starting spatial condition and the first ending spatial condition of the identified change, a first subset of the spatial condition changes being associated with respective disengagement likelihoods representing how likely respective ones of the first subset of the spatial condition changes correspond to a user beginning to disengage from the presentation on the portable device;
• and
• cause the user attentiveness data to be transmitted via the network to at least one of the first server or a second server.