Factor discussion

[jdkent]

variable naming,

Conversation about transforms whose outputs are dependent on variable (i.e., column) values.

onset	duration	trial_type
0	0.5	blue
2.5	0.5	blue
5.7	0.5	red
8.9	0.5	red

Example:
Factor("trial_type") will create 2 new variables: trial_type.blue and trial_type.red

it may be confusing to know what the generated variable names will be and referencing the "yet-to-be" generated names in the same model specification.