An investigator into the life expectancy of IV drug abusers divides sample of patients into HIV positive and HIV negative groups. What type of data does this division constitute -

Scales can be: Qualitative: Categorical scales: Nominal : eg: names of countries . It&;s like naming or labeling . Dichotomous : eg: yes/no, presence/absence. Ordinal : severity of disease: mild/moderate/severe.eg: staging of cancer, kuppusamy socioeconomic class. Quantitative: Metric scales: Interval Ratio Note: Dichotomous is a subtype of nominal with 2 categories .