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; 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
)