Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:The antibacterial activity of manuka extract was tested using absorbance (Patton et al. 2006) on a microplate reader at 595nm for 36hrs at 30°C.
Field Experiment
I. Soil Quality Tests
The bait laminar test is a good indicator of soil invertebrates and soil microorganisms.
Category: