As part of an outreach program, a group of doctors is assigned to a rural area affected by significant cases of preventable infectious disease. The goal of the program is to provide local residents with wearable devices they can use in their homes to prevent the spread of disease. The devices are simply designed and easy to put on, intentional qualities to prevent the devices from being used incorrectly, which would render them ineffective.
Because the area has few resources to support the outreach efforts and traveling to the area is difficult, the doctors decide to use the back of a chair to demonstrate the device rather than bringing a full-size mannequin. Despite research proving the effectiveness of the device and the doctors meeting with a large portion of the local population, they do not see the large drop in infectious disease cases they had expected.
Which of the following assumptions likely led to these unexpected results?