title: Showing similarity of results given by two methods: a commentary.
abstract: There is a frequent need in the environmental sciences to show the similarity of the results given by two analytical methods. This cannot, however, be done within the conventional 'there is a difference' statistical hypothesis setting of, among others, Student's t-test. We demonstrate here a more appropriate approach that originates from drug testing and that can be applied with standard statistical software. It is a challenging approach, as it requires quantification of the similarity limit. If no pre-determined value is given for similarity, a potential data-supported similarity limit can be explored from the data. The approach has numerous other potential application areas, e.g. parallelism of regression slopes, homogeneity of variances and lack of interaction.
authors.affiliation: Finnish Environment Institute, P.O. Box 140, FIN-00251 Helsinki, Finland. hannu.rita@helsinki.fi
authors.forename: Hannu
authors.initials: H
authors.lastname: Rita
authors.forename: Petri
authors.initials: P
authors.lastname: Ekholm
mesh_terms: D003627:Data Interpretation, Statistical; D004463:Ecology / Q000379:methods*; D015233:Models, Statistical; D012984:Software; D013810:Therapeutic Equivalency