LON-CAPA Help

The Overall Problem Statistics page lets you view performance statistics on all problems. This page displays the following data about the Folders/Sequences selected for evaluation:

• #Items

  The number of assessment items (problem parts) in the sequence.

• Score and Count Statistics

  For the score, the product of the problem weight, the percent awarded, the count, and the number of problem parts correct, the following data are computed:

  • MEAN

  • Standard Deviation

  • Maximum

    The highest achieved score or count in the data set.

  • Minimum

    The lowest achieved score or count in the data set.

  • N

    The number of students evaluated.

• KR-21

  This statistic measures the internal reliability of the data set. This statistic is relevant for exams only. Let K be the number of items in your test, M the mean score on the test, s the standard deviation of the scores on your test, then the KR-21 statistic, rk, is given by the formula

  
  

  rk=  K K-1 ·  1-(M*(K-M)) Ks2

You have the option to have this statistical data output to an Excel file.

Clicking on the problem name will open a view of the problem in a separate window.