Table 1. Summary of strengths and weaknesses of selected contact pattern collection methods.

Method	Strengths	Weaknesses
Observation	Less susceptible to error than survey data [5]	Difficult to observe all individuals simultaneously [3]
Diaries and surveys	Allows for the specification of the type and frequency of the contact events [4]	Recall and non-response bias [4] Focused on the ego network (a network whose information source is a single node) [6] Costly [4] Often have a small sample size [7]
RFID* tags	Relatively inexpensive and easy to use [4] Detect close-range encounters [8]	Technological constraints (e.g. power supply) [2] Radio-technology limitations e.g. radio-wave interference [9] Only provide information about the individuals wearing a tag [4]

* RFID: radio-frequency identification