\label{Statistics_Sequence} The \textbf{Overall Problem Statistics} page lets you view performance statistics on all problems. This page displays the following data about the \textbf{Folders/Sequences} selected for evaluation: \begin{itemize} \item \textbf{\#Items} The number of assessment items (problem parts) in the sequence. \item \textbf{Score} and \textbf{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: \begin{itemize} \item \textbf{MEAN} \item \textbf{Standard Deviation} \item \textbf{Maximum} The highest achieved score or count in the data set. \item \textbf{Minimum} The lowest achieved score or count in the data set. \item \textbf{N} The number of students evaluated. \end{itemize} \item \textbf{KR-21} This statistic measures the internal reliability of the data set. \textbf{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 $$ rk=\frac{K}{K-1}\cdot \frac{1-(M*(K-M))}{Ks^2} $$ \end{itemize} 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.