A net allows you to collect a greater range of benthic macroinvertebrates and more accurately assess the diversity of the community. The kick-net method (or scuff method) shows you how to dislodge the stones on the streambed and collect the invertebrates living on or in-between them. When you enter your data into the NZ Water Citizens website - https://nzwatercitizens.co.nz/ - you can use the online calculator to calculate a health score.