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Class "SingleChoice"

Source: R/SingleChoice.R
SingleChoice-class.Rd

Class SingleChoice is responsible for creating single-choice assessment tasks according to the QTI 2.1 standard.

Slots

identifier

A character representing the unique identifier of the assessment task. By default, it is generated as 'id_task_dddd', where dddd represents random digits.

title

A character representing the title of the XML file associated with the task. By default, it takes the value of the identifier.

content

A list of character content to form the text of the question, which can include HTML tags. For tasks of the Entry type, it must also contain at least one instance of Gap objects, such as TextGap, TextGapOpal, NumericGap, or InlineChoice.

prompt

An optional character representing a simple question text, consisting of one paragraph. This can supplement or replace content in the task. Default is "".

points

A numeric value, optional, representing the number of points for the entire task. Default is 1, but pay attention:

  • For tasks of the Entry type, it is calculated as the sum of the gap points by default.

  • For tasks of the DirectedPair, the default is calculated as 0.5 points per pair.

  • For tasks of the MatchTable type, it can also be calculated as the sum of points for individual answers, when provided.

  • For tasks of the MultipleChoice type, points is numeric vector and required. Each number in this vector determines the number of points that will be awarded to a candidate if they select the corresponding answer. The order of the scores must match the order of the choices. It is possible to assign negative values to incorrect answers. All answers with a positive score are considered correct.

feedback

A list containing feedback messages for candidates. Each element of the list should be an instance of either ModalFeedback, CorrectFeedback, or WrongFeedback class.

calculator

A character, optional, determining whether to show a calculator to the candidate. Possible values:

  • "simple"

  • "scientific"

files

A character vector, optional, containing paths to files that will be accessible to the candidate during the test/exam.

metadata

An object of class QtiMetadata that holds metadata information about the task.

choices

A character vector defining a set of answer options in the question.

choice_identifiers

A character vector, optional, containing a set of identifiers for answers. By default, identifiers are generated automatically according to the template "ChoiceD", where D is a letter representing the alphabetical order of the answer in the list.

shuffle

A boolean value indicating whether to randomize the order in which the choices are initially presented to the candidate. Default is TRUE.

orientation

A character, determining whether to place answers in vertical or horizontal mode. Possible values:

  • "vertical" - Default.

  • "horizontal"

solution

A numeric value, optional. Represents the index of the correct answer in the choices slot. By default, the first item in the choices slot is considered the correct answer. Default is 1.

Examples

sc <- new("SingleChoice",
          identifier = "id_task_1234",
          title = "Single Choice Task",
          content = list("<p>Pick up the right option</p>"),
          prompt = "Plain text, can be used instead of content",
          points = 2,
          feedback = list(new("WrongFeedback", content = list("Wrong answer"))),
          calculator = "scientific-calculator",
          files = "text_book.pdf",
          choices = c("option 1", "option 2", "option 3", "option 4"),
          choice_identifiers = c("ChoiceA", "ChoiceB", "ChoiceC", "ChoiceD"),
          shuffle = TRUE,
          orientation = "vertical",
          solution = 2)