disp_DP {tlda}R Documentation

Calculate Gries's deviation of proportions

Description

This function calculates Gries's dispersion measure DP (deviation of proportions). It offers three different formulas and allows the user to choose the directionality of scaling, i.e. whether higher values denote a more even or a less even distribution. It also offers the option of calculating frequency-adjusted dispersion scores.

Usage

disp_DP(
  subfreq,
  partsize,
  directionality = "conventional",
  formula = "egbert_etal_2020",
  freq_adjust = TRUE,
  freq_adjust_method = "even",
  unit_interval = TRUE,
  digits = NULL,
  verbose = TRUE,
  print_score = TRUE,
  suppress_warning = FALSE
)

Arguments

subfreq

A numeric vector of subfrequencies, i.e. the number of occurrences of the item in each corpus part

partsize

A numeric vector specifying the size of the corpus parts

directionality

Character string indicating the directionality of scaling. See details below. Possible values are "conventional" (default) and "gries"

formula

Character string indicating which formula to use for the calculation of DP. See details below. Possible values are "egbert_etal_2020" (default), "gries_2008", "lijffit_gries_2012".

freq_adjust

Logical. Whether dispersion score should be adjusted for frequency (i.e. whether frequency should be 'partialed out'); default is FALSE

freq_adjust_method

Character string indicating which method to use for devising dispersion extremes. See details below. Possible values are "even" (default) and "pervasive"

unit_interval

Logical. Whether frequency-adjusted scores that exceed the limits of the unit interval should be replaced by 0 and 1; default is TRUE

digits

Rounding: Integer value specifying the number of decimal places to retain (default: no rounding)

verbose

Logical. Whether additional information (on directionality, formulas, frequency adjustment) should be printed; default is TRUE

print_score

Logical. Whether the dispersion score should be printed to the console; default is TRUE

suppress_warning

Logical. Whether warning messages should be suppressed; default is FALSE

Details

The function calculates the dispersion measure DP based on a set of subfrequencies (number of occurrences of the item in each corpus part) and a matching set of part sizes (the size of the corpus parts, i.e. number of word tokens).

In the formulas given below, the following notation is used:

The value "gries_2008" implements the original version proposed by Gries (2008: 415). Note that while the following formula represents Gries scaling (0 = even, 1 = uneven), in the current function the directionality is controlled separately using the argument directionality.

\frac{\sum_i^k |t_i - w_i|}{2} (Gries 2008)

The value "lijffit_gries_2012" implements the modified version described by Lijffit & Gries (2012). Again, the following formula represents Gries scaling (0 = even, 1 = uneven), but the directionality is handled separately in the current function. The notation min\{w_i\} refers to the w_i value of the smallest corpus part.

\frac{\sum_i^k |t_i - w_i|}{2} \times \frac{1}{1 - min\{w_i\}} (Lijffijt & Gries 2012)

The value "egbert_etal_2020" (default) selects the modification suggested by Egbert et al. (2020: 99). The following formula represents conventional scaling (0 = uneven, 1 = even). The notation min\{w_i: t_i > 0\} refers to the w_i value among those corpus parts that include at least one occurrence of the item.

1 - \frac{\sum_i^k |t_i - w_i|}{2} \times \frac{1}{1 - min\{w_i: t_i > 0\}} (Egbert et al. 2020)

Value

A numeric value

Author(s)

Lukas Soenning

References

Carroll, John B. 1970. An alternative to Juilland’s usage coefficient for lexical frequencies and a proposal for a standard frequency index. Computer Studies in the Humanities and Verbal Behaviour 3(2). 61–65. doi:10.1002/j.2333-8504.1970.tb00778.x

Egbert, Jesse, Brent Burch & Douglas Biber. 2020. Lexical dispersion and corpus design. International Journal of Corpus Linguistics 25(1). 89–115. doi:10.1075/ijcl.18010.egb

Gries, Stefan Th. 2008. Dispersions and adjusted frequencies in corpora. International Journal of Corpus Linguistics 13(4). 403–437. doi:10.1075/ijcl.13.4.02gri

Gries, Stefan Th. 2022. What do (most of) our dispersion measures measure (most)? Dispersion? Journal of Second Language Studies 5(2). 171–205. doi:10.1075/jsls.21029.gri

Gries, Stefan Th. 2024. Frequency, dispersion, association, and keyness: Revising and tupleizing corpus-linguistic measures. Amsterdam: Benjamins. doi:10.1075/scl.115

Juilland, Alphonse G. & Eugenio Chang-Rodríguez. 1964. Frequency dictionary of Spanish words. The Hague: Mouton de Gruyter. doi:10.1515/9783112415467

Lijffijt, Jefrey & Stefan Th. Gries. 2012. Correction to Stefan Th. Gries’ ‘Dispersions and adjusted frequencies in corpora’. International Journal of Corpus Linguistics 17(1). 147–149. doi:10.1075/ijcl.17.1.08lij

Rosengren, Inger. 1971. The quantitative concept of language and its relation to the structure of frequency dictionaries. Études de linguistique appliquée (Nouvelle Série) 1. 103–127.

Examples

disp_DP(
  subfreq = c(0,0,1,2,5), 
  partsize = rep(1000, 5),
  directionality = "conventional",
  formula = "gries_2008",
  freq_adjust = FALSE)


[Package tlda version 0.1.0 Index]