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Start elicitation

Source: R/cont_start.R
cont_start.Rd

[Experimental]

cont_start() initialises an elic_cont object which stores important metadata for the data collected during the elicitation process of continuous variables.

Usage

cont_start(
  var_names,
  var_types,
  elic_types,
  experts,
  ...,
  title = "Elicitation",
  verbose = TRUE
)

Arguments

var_names

character vector with the name of the estimated variables.

var_types

character string with short codes indicating the variable type. If only one var_type is provided, its value is recycled for all variables. See Variable types for more.

elic_types

character string with short codes indicating the elicitation type. If only one elic_type is provided, its value is recycled for all variables. See Elicitation Types for more.

experts

numeric indicating the number of experts participating in the elicitation process.

...

Unused arguments, included only for future extensions of the function.

title

character, used to bind a name to the object.

verbose

logical, if TRUE it prints informative messages.

Value

An object of class elic_cont binding metadata related to the elicitation process. These metadata are used by other functions to validate the correctness of the provided data.

Variable types

Variable types must be provided as a single string containing short codes, e.g. "pPN".

Valid short codes are:

  • Z: integers, when the estimate must be an integer number in the interval (-Inf, Inf).

  • N: positive integers, when the estimate must be an integer number in the interval (0, Inf).

  • z: negative integers, when the estimate must be an integer number in the interval (-Inf, 0].

  • R: reals, when the estimate must be a real number in the interval (-Inf, Inf).

  • s: positive reals, when the estimate must be a real number in the interval (0, Inf).

  • r: negative reals, when the estimate must be a real number in the interval (-Inf, ].

  • p: probability, when the estimate must be a real number in the interval (0, 1).

Elicitation types

Elicitation types must be provided as a single string containing short codes, e.g. "134".

Valid short codes are:

  • 1: one point elicitation, when only the best estimate is provided.

  • 3: three points elicitation, when the minimum, maximum, and best estimates are provided.

  • 4: four points elicitation, when the minimum, maximum, best, and confidence estimates are provided.

References

Hemming, V., Burgman, M. A., Hanea, A. M., McBride, M. F., & Wintle, B. C. (2018). A practical guide to structured expert elicitation using the IDEA protocol. Methods in Ecology and Evolution, 9(1), 169–180. https://doi.org/10.1111/2041-210X.12857

See also

Other cont data helpers: cont_add_data(), cont_get_data(), cont_sample_data(), summary.cont_sample()

Author

Sergio Vignali

Examples

# Create the elic_cont object for an elicitation process that estimates 3
# variables, the first for a one point estimation of a positive integer, the
# second for three points estimation of a negative real, and the last for a
# four point estimation of a probability
my_elicit <- cont_start(var_names = c("var1", "var2", "var3"),
                        var_types = "Nrp",
                        elic_types = "134",
                        experts = 4)
#> ✔ <elic_cont> object for "Elicitation" correctly initialised
my_elicit
#> 
#> ── Elicitation ──
#> 
#> • Variables: "var1", "var2", and "var3"
#> • Variable types: "N", "r", and "p"
#> • Elicitation types: "1p", "3p", and "4p"
#> • Number of experts: 4
#> • Number of rounds: 0

# A title can be added to bind a name to the object:
my_elicit <- cont_start(var_names = c("var1", "var2", "var3"),
                        var_types = "Nrp",
                        elic_types = "134",
                        experts = 4,
                        title = "My elicitation")
#> ✔ <elic_cont> object for "My elicitation" correctly initialised
my_elicit
#> 
#> ── My elicitation ──
#> 
#> • Variables: "var1", "var2", and "var3"
#> • Variable types: "N", "r", and "p"
#> • Elicitation types: "1p", "3p", and "4p"
#> • Number of experts: 4
#> • Number of rounds: 0
# Notice that if var_types and elic_types are provided as single character,
# their value is recycled and applied to all variables. In the following
# example all three variables will be considered for a four point estimation
# to estimate a probability:
my_elicit <- cont_start(var_names = c("var1", "var2", "var3"),
                        var_types = "p",
                        elic_types = "4",
                        experts = 4)
#> ✔ <elic_cont> object for "Elicitation" correctly initialised
my_elicit
#> 
#> ── Elicitation ──
#> 
#> • Variables: "var1", "var2", and "var3"
#> • Variable type: "p"
#> • Elicitation type: "4p"
#> • Number of experts: 4
#> • Number of rounds: 0