--- loncom/html/adm/help/tex/Statistics_Overall_Key.tex 2005/06/16 23:08:13 1.7
+++ loncom/html/adm/help/tex/Statistics_Overall_Key.tex 2008/02/22 19:22:21 1.10
@@ -1,32 +1,32 @@
-\label{Statistics_Key}
+\label{Statistics_Overall_Key}
The \textbf{Overall Problem Statistics} page displays the following
data about the problems currently in the course:
\begin{description}
-\item{\textbf{\#Stdnts}} Total number of students attempting the problem.
+\item{\textbf{\#Stdnts}}: Total number of students attempting the problem.
-\item{\textbf{Tries}} Total number of attempts to solve the problem.
+\item{\textbf{Tries}}: Total number of attempts to solve the problem.
-\item{\textbf{Max Tries}} Largest number of attempts to solve the problem by a student.
+\item{\textbf{Max Tries}}: Largest number of attempts to solve the problem by a student.
-\item{\textbf{Mean Tries}} Average number of attempts.
+\item{\textbf{Mean Tries}}: Average number of attempts.
-\item{\textbf{S.D. tries}} Standard Deviation of the tries.
+\item{\textbf{S.D. tries}}: Standard Deviation of the tries.
-\item{\textbf{Skew Tries}} Skewness of the students tries.
+\item{\textbf{Skew Tries}} Skewness of the students' tries.
\[ \frac{\sqrt{ \sum{(Xi - Mean)^3} / \#Stdnts}}{\sigma^3} \]
-\item{\textbf{\#YES}} Number of students who solved the problem correctly.
+\item{\textbf{\#YES}}: Number of students who solved the problem correctly.
-\item{\textbf{\#yes}} Number of students who solved the problem by override.
+\item{\textbf{\#yes}}: Number of students who solved the problem by override.
-\item{\textbf{\%Wrng}} Percentage of students who tried to solve the problem but were unable to.
+\item{\textbf{\%Wrng}}: Percentage of students who tried to solve the problem but were unable to.
-\item{\textbf{DoDiff}} Degree of Difficulty of the problem.
+\item{\textbf{DoDiff}}: Degree of Difficulty of the problem.
-This statistics gives a measure of how many attempts it took the
+This statistics give a measure of how many attempts it took the
students to get the problem correct. Those students who did not get
the problem correct are not counted. A value close to 0 indicates
most students who got the problem correct did so on the first attempt.
@@ -37,7 +37,7 @@ there were no attempts made on the probl
\[ 1 - \frac{\#YES+\#yes}{Tries} \]
-\item{\textbf{DoDisc}} Degree of Discrimination of the problem.
+\item{\textbf{DoDisc}}: Degree of Discrimination of the problem.
The students are grouped based on their scores on the sequence which
contains the homework problem. The percent score of the bottom 25\% of
@@ -48,18 +48,18 @@ poor students answered it correctly. Co
all of the good students got the problem wrong and the bad students did
well.
-\item{\textbf{weight}} The weight of the problem in the course (``points'').
+\item{\textbf{weight}}: The weight of the problem in the course (``points'').
The value shown is the weight of the problem for the individual computing the
statistics. Individual student or section variations are not shown.
\end{description}
-\textbf{Sequence Statistics}, that is compiled statistics on problems based on
+\textbf{Sequence Statistics}: Compiled statistics on problems based on
their containing sequence, are also shown. The following data are shown:
\begin{description}
-\item{\textbf{\#Items}} The number of problem parts in the sequence.
+\item{\textbf{\#Items}}: The number of problem parts in the sequence.
\item{\textbf{Score Mean}, \textbf{Score STD}, \textbf{Score Max} \textbf{Score Min}}
The mean, standard deviation, maximum, and minimum of the scores of
@@ -67,8 +67,8 @@ the selected students on the given seque
\item{\textbf{Score N}} The number of the selected students who submitted answers to problem parts in the sequence.
-\item \textbf{Count Mean}, \textbf{Count STD}, \textbf{Count Max}, \textbf{Count Min}
-The mean, standard deviation, maximum, and minum count of correct
+\item \textbf{Count Mean}, \textbf{Count STD}, \textbf{Count Max}, \textbf{Count Min}:
+The mean, standard deviation, maximum, and minimum count of correct
problem parts of the selected students on the given sequence.
\item \textbf{Count N} The number of the selected students who submitted answers to problem parts in the sequence.
@@ -77,7 +77,7 @@ problem parts of the selected students o
To compute the KR-21 reliability statistic the following formula is used:
-\[KR-21 = \frac{K}{K-1} \cdot \frac{1-(M \cdot (K-M))}{K \cdot s^{2}}\]
+\[KR-21 = \frac{K}{K-1} \cdot \left(1- \frac{M \cdot (K-M)}{K \cdot s^{2}} \right)\]
Where
\begin{description}