Description Usage Arguments Details Value Note

Determines which answers in the answer key are "edge" options, and which ones are "middle" options.

1 | ```
answer_key_edge_or_not(exam, numchoicesperitem = NULL, check_format = FALSE)
``` |

`exam` |
A data.frame object containing a test that follows the formatting of a typical Scantron file. |

`numchoicesperitem` |
A vector which has the same length as the number of questions on the test, where each element in the vector corresponds to the number of choices there were for each of the questions on the test. For example, if your test had 35 questions which each had 5 options, numchoicesperitem = rep(5, 35). |

`check_format` |
a logical value (default = TRUE) indicating whether the "exam" object should be tested for correct formatting. |

If a question has n options, then the first option and the nth option are "edge" options. The remaining n-2 options are "middle" options.

Returns a vector which is the same length as the number of questions on the test. Each element in the vector corresponds to one of the questions, and contains either "EDGE" or "MIDDLE", depending on whether the answer for that question is an edge option or a middle option.

The argument "exam" must be in the format of a typical Scantron results file. Column 1 should correspond to ID (e.g., student number); column 2 should correspond to DEPT (e.g., MATH); column 3 should correspond to COURSE CODE (e.g., 1051); the remaining columns should each correspond to one of the questions on the test. The header of the data frame should contain the column names, and row 1 of the data frame should contain the answer key for the test. For example, if you had an exam with 25 students and 40 questions, the data.frame object should have 26 rows and 43 columns.

The "check_format" argument defaults to null. If this is left as null, the function will call
the `num_choices_per_item`

function, which will do its best to guess the number of options
for each question. This is done by looking at the student answers and finding the
"largest" answer for each question. For example, if at least one student answered "E", but no students
answered "F", the function would guess that there were 5 options for that question.

Embedding an R snippet on your website

Add the following code to your website.

For more information on customizing the embed code, read Embedding Snippets.