These variables could be dichotomous, ordinal or nominal variables. Tetrachoric correlation assumes that the variable underlying each dichotomous measure is normally distributed. This can be shown by assigning two distinct numerical values to the dichotomous variable. The original dichotomous discriminant analysis was developed by Sir Ronald Fisher in 1936. Laminar venation is highly variable, being dichotomous to pinnate to densely reticulate. Specifically, Collins refers to this as the construct of dichotomous oppositional difference. It has stems long with dichotomous branching. The articulated leaflets lack a midrib, and are broad with subparallel dichotomous venation. We do recognize the unbalanced and parochial nature of this dichotomous division. The sexual attraction to children appears to fall along a continuum instead of being dichotomous. Moreover, the cognitive distortion due to dichotomous thinking leads the individual to binge. There are also truly dichotomous values to be decided by mere convenience. Having dichotomous preferences means that a voter has bi-level preferences for the candidates. However, having dichotomous preferences when there are three or more candidates is not typical. This function has the structure of the Rasch model for dichotomous data.