factorH: syntax

Formula syntax at a glance

All high-level functions use standard R model formulas:
response ~ factorA + factorB + factorC

• + lists main effects - Interactions are handled internally. You do not need to write A:B or A*B.
• The response (left of ~) must be numeric (e.g., a Likert score coded as 1..5 stored as numeric).

Examples below use the included dataset mimicry.

library(factorH)
data(mimicry, package = "factorH")
str(mimicry)

Predictors should be factors. If not, functions will coerce them.

What is allowed?

# One factor (KW-style):  
  liking ~ condition

# Two factors (SRH-style):  
  liking ~ gender + condition

# Three or more factors (k-way):  
  liking ~ gender + condition + age_cat

You do not need to write gender:condition or gender*condition. The package will build all needed interactions internally when relevant.

Numeric response (Likert note)

The response must be numeric. For Likert-type items (e.g., 1 = strongly disagree … 5 = strongly agree), keep them numeric; rank-based tests are robust for such ordinal-like data.

If your Likert is accidentally a factor or character, coerce safely:

# if stored as character "1","2",...:
mimicry$liking <- as.numeric(mimicry$liking)
# if stored as factor with labels "1","2",...:
mimicry$liking <- as.numeric(as.character(mimicry$liking))

C:8WGoPl2c1c40c845ef-syntax.R