In the data source scree you are choosing how you would like to gather dimensions on a home. Once you select a data source you cannot change it, so choose wisely.
Map Trace – This option can be used to trace an existing home from Google Map satellite imagery. Recommended for block loads which the home is not obstructed by large amounts of tree coverage.
Text – This option allows a user to manually enter dimensions. It is recommended for room-by-room loads, or if the user already has measurements or is working off a set of plans.
More data sources coming soon - As technology continues to evolve we will keep adding additional methods to obtain dimensions. Soon you will be able to use your phone's camera and augmented reality to measure rooms, or even import a set of plans. Keep checking back for more info on data sources.