ABSTRACT
The data set of 33 known invasive alien species and a few non-invasive species has been obtained by the invasive specialists group attached to the Ministry of Environment and Renewable Resources, Sri Lanka. It contained single-valued observations of 12 parameters and invasion risk scores which are obtained from the NRA procedure using the checklist prepared and accepted by the Ministry of Environment and Renewable Resources, Sri Lanka, after broad stakeholder participation and discussion. In the process of interval data formulation, scores assigned to the linguistic labels of qualitative parameters and real data of quantitative parameters have been converted into intervals by performing width adjustments considering those values as centers. It can be seen that NRA scores of species Austroeupatorium inulifolium , Cuscuta campestris , and Acacia mearnsii stand much closer to the upper boundary of the approximated level where the NRA of Panicum maximum and Pueraria montana stand closer to the lower boundary of the approximated level.
