Categorical variables are also known as qualitative (or discrete) variables. These categorical variables can be further classified as being nominal, dichotomous or ordinal variables. Each of these types of categorical variable (i.e., nominal, dichotomous and ordinal) has what are known as categories or levels. These categories or levels are the descriptions that you give a variable that help to explain how variables should be measured, manipulated and/or controlled.
BetimolÂ® (timolol ophthalmic solution), 0.25% and 0.5%, is a non-selective beta-adrenergic antagonist for ophthalmic use. The chemical name of the active ingredient is (S)-1-[(1,1-dimethylethyl)amino]-3-[(4-(4-morpholinyl)-1,2,5-thiadiazol-3-yl]oxy]-2-propanol. Timolol hemihydrate is the levo isomer.
B. splendens is more accurately called by its scientific name or Siamese fighting fish, to avoid confusion with the other species in the genus. In popular culture. The titular character in the novel Rumble Fish (novel) and subsequent film Rumble Fish is a Siamese fighting fish. The Siamese fighting fish (Betta splendens), also sometimes colloquially known as the betta, is a species in the gourami family which is popular as an aquarium fish. Bettas can be territorial fish and are prone to high levels of aggression towards each other.