Define a scored scale

Creates a scale definition that groups items and specifies how composite scores are computed. The scale carries scoring rules used by score_scales() and measurement structure used by reliability_report(), item_report(), and cfa_syntax().

Usage

sf_scale(
  id,
  label,
  items,
  method = c("mean", "sum"),
  min_valid = NULL,
  reverse_items = NULL,
  weights = NULL
)

Arguments

id

Character. A unique identifier for this scale. Referenced in the scale_id argument of sf_item().

label

Character. A human-readable name for the scale, used in reports and codebooks.

items

Character vector. The id values of items that belong to this scale. Order controls presentation in reports, while scoring uses the same item IDs regardless of order.

method

Character. Scoring method. Either "mean" (default) or "sum".

min_valid

Integer or NULL. The minimum number of non-missing items required to compute a score for a respondent. When NULL, all items must be present. Used by score_scales().

reverse_items

Character vector or NULL. A subset of items that are reverse-coded. These can also be flagged at the item level with the reverse argument in sf_item(). Both sources are respected.

weights

Numeric vector or NULL. Item weights for weighted scoring. Must have the same length as items if supplied. score_scales() applies the weights to either method = "mean" or method = "sum".

Value

An object of class sf_scale (a named list).

See also

sf_item(), score_scales(), reliability_report()

Examples

sat_scale <- sf_scale(
  id            = "satisfaction",
  label         = "Customer Satisfaction",
  items         = c("sat_overall", "sat_speed", "sat_quality"),
  method        = "mean",
  min_valid     = 2,
  reverse_items = NULL
)