1. If more than one observer is to be used, make sure the actions of one will not influence the other. If possible, place them in areas where they cannot view each other. 2. Make sure the observers...

1. If more than one observer is to be used, make sure the actions of one will not influence the other. If possible, place them in areas where they cannot view each other.

2. Make sure the observers don’t have to work so hard or so long at collecting data that they become fatigued and begin collecting inaccurate data.