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Look up norm table values based on raw scores and group affiliations

lookup_norms.Rd

Transforms raw values to norm values based on a norm table. If group affiliations are provided, these are used to identify the correct norm values. If no group affiliations are provided, norm values are looked up based on raw scores only. In case of ambiguities (e.g., multiple norm values for the same raw score), NA is returned and a message is printed.

Usage

lookup_norms(
  rawscores,
  group = NULL,
  normtable,
  from = "raw",
  to = "T",
  group_label = names(group),
  label = NULL
)

Arguments

rawscores

A vector with raw scores.

group

A vector with group affiliations or a list with vectors for multiple group categorizations. If NULL (default), no group affiliations are used.

normtable

An excel file name or a data frame containing a norm table.

from

Label of the raw score variable in file.

to

Label of the norm score variable in file.

group_label

Label of the group variable in file or a list with group labels for multiple group categorizations. If NULL (default), "group" is used as group label.

label

Item label of the resulting variable. If NULL (default), no label is set.

Value

A vector with norm values. If ambiguities occur, NA is returned for the respective raw score(s) and a message is printed.

Examples

normtable <- data.frame(
  age = rep(c(6, 8, 6, 8), each = 11),
  gender = rep(c("m", "w"), each = 22),
  raw =  rep(0:10, 4),
  T = rep(c(40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60,
            37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57), 2) + rep(c(0,5), each = 22)
)
rawscores <- c(5,5,3,1)
group_age <- c("6", "8", "6", "8")
group_gender <- c("m", "m", "w", "w")

lookup_norms(rawscores, group = list(age = group_age, gender = group_gender), normtable)
#> ║T_score 
#> ║Data type is numeric
#> ║ 
#> ║Length is 4 (0 NA; 0 invalid)
#> ║[1] 50 47 51 44

## When group values are not specified exactly, raw scores can be ambiguous:
lookup_norms(rawscores, group = list(gender = group_gender), normtable = normtable)
#> ! Multiple values found for raw 5 and group m (50, 47). NA returned.
#> ! Multiple values found for raw 5 and group m (50, 47). NA returned.
#> ! Multiple values found for raw 3 and group w (51, 48). NA returned.
#> ! Multiple values found for raw 1 and group w (47, 44). NA returned.
#> ! Type of T_score is missing and is estimated as 'logical'.
#> ║T_score 
#> ║Data type is logical
#> ║ 
#> ║Length is 4 (4 NA; 0 invalid)
#> ║[1] NA NA NA NA

lookup_norms(rawscores, normtable = normtable)
#> ! Multiple values found for raw 5 (50, 47, 55, 52). NA returned.
#> ! Multiple values found for raw 5 (50, 47, 55, 52). NA returned.
#> ! Multiple values found for raw 3 (46, 43, 51, 48). NA returned.
#> ! Multiple values found for raw 1 (42, 39, 47, 44). NA returned.
#> ! Type of T_score is missing and is estimated as 'logical'.
#> ║T_score 
#> ║Data type is logical
#> ║ 
#> ║Length is 4 (4 NA; 0 invalid)
#> ║[1] NA NA NA NA