amassing evidence
appraisal
assessment
assortment
bolting
categorization
clarification
classification
close inquiry
colature
culling
department of investigation
destructive distillation
detection
detective work
distillation
edulcoration
elution
elutriation
essentialization
evaluation
exhaustive study
extraction
factoring
filtering
filtration
gauging
gradation
grouping
hearing
identification
indagation
investigation
investigative bureau
leaching
legislative investigation
legwork
lixiviation
percolation
perscrutation
placement
probe
purification
ranking
refinement
research
riddling
screening
selection
separation
drifting
gifting
lifting
shifting