[LON-CAPA-cvs] cvs: loncom /html/adm/help/tex Statistics_Sequence.tex

[matthew]

matthew		Mon Jul 12 15:28:22 2004 EDT

  Added files:                 
    /loncom/html/adm/help/tex	Statistics_Sequence.tex 
  Log:
  Help on sequence level statistics.
  
  

Index: loncom/html/adm/help/tex/Statistics_Sequence.tex
+++ loncom/html/adm/help/tex/Statistics_Sequence.tex
\label{Statistics_Sequence}

The \textbf{Overall Problem Statistics} page displays the following 
data about the \textbf{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 both the score, the product of the problem weight and the percent awarded,
and the count, 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}