simple_effects_analysis function

Simple Effects Analysis

Conduct a simple effects analysis to probe a two-way interaction effect. See Field et al. (2012, ISBN: 978-1-4462-0045-2).

simple_effects_analysis(
  data = NULL,
  dv_name = NULL,
  iv_1_name = NULL,
  iv_2_name = NULL,
  iv_1_levels = NULL,
  iv_2_levels = NULL,
  print_contrast_table = "weights_sums_and_products",
  output = NULL
)

Arguments

• data: a data object (a data frame or a data.table)
• dv_name: name of the dependent variable (DV)
• iv_1_name: name of the first independent variable (IV1), whose main effects will be examined in the first set of contrasts
• iv_2_name: name of the second independent variable (IV2), whose simple effects at each level of IV1 will be examined in the second set of contrasts
• iv_1_levels: ordered levels of IV1
• iv_2_levels: ordered levels of IV2
• print_contrast_table: If print_contrast_table = "weights_sums_and_products", contrasts' weights, sums of the weights and products will be printed. If print_contrast_table = "weights_only", only the contrasts will be printed.
• output: output can be one of the following: "lm_object", "table", "weights_only", "weights_sums_and_products", "all" By default, output = NULL, and there will be no output from the function other than the tables of simple effects and constrasts which will be printed on the console by default.

Returns

By default, the function will print a table of contrasts and a table of simple effects.

Examples

factorial_anova_2_way(
  data = mtcars, dv_name = "mpg", iv_1_name = "vs",
  iv_2_name = "am", iterations = 100, plot = TRUE)
simple_effects_analysis(
  data = mtcars, dv_name = "mpg", iv_1_name = "vs",
  iv_2_name = "am")