1) Why is the ID so important?

Unique ID is also important because it avoid duplicates or more copies of the same identification number in the electronic data entry form. Unique ID can be used to link confidential information that are often removed from the original data collection forms and kept a part. It is hard or often impossible to identify individuals by names, or location without unique identifier. When the original data collection forms are lost or muddled up; without unique ID it can be a serious problem to know which data have been entered into the computer (although some computer assigns automatic identification number) if data capture has begun already.

2) What happens if different questionnaires (and picture files) cannot be linked?

Failure to link image files to the questionnaire can result in frustration, waste of resources, time and valuable information.

It might take time and money to find experts who will be willing to clean and analyse such data.

3) Share experiences using tablets or phones in data collection.

Electronic data collection tools including phones, tablets and PDAs are very useful and easy to carry, however lack of power supplier and or problem with battery can hamper their use in remote settings. Furthermore, they are not well-suited for areas with level of insecurity or robbery. They should be used with care, if the data collection involves taking pictures and geographic coordinates.

Despite some of the disadvantages mentioned, data collection and validation are very quickly done using mobile devices (i.e. telephone). Errors can be corrected immediately before leaving the field. Information about individual, their vaccination status and geographic locations can be collected and sent instantaneously to the data warehouse for rapid analysis.

Regardless of whichever electronic device to be used, one needs to have back of data collection forms in paper format/hard copy, this will help in case of unforeseen events.