Changes between Version 3 and Version 4 of BoltTutorialAnalytics

Timestamp:

Aug 18, 2008, 4:11:42 PM (16 years ago)

Author:

davea

Comment:

--

BoltTutorialAnalytics

@@ -4 +4 @@
 
 Suppose you have two alternative lessons for a given concept.
-They may be completely different,
-or they may differ in appearance.
 Which is better?
-Or is each better for some identifiable subset of students?
+Or is each better for an identifiable subset of students?
 To investigate, create a '''micro-experiment'''
 in which students are randomly shown one lesson or the other,
-and then perform an exercise.
+and then perform the same exercise.
+
+The random selection of lesson is accomplished using a new
+Bolt control structure, '''select''':
 {{{
-function show_lesson() {
-    return select(
-        name('show_lesson'),
-        valuator('rand'),
-        lesson(
-            filename('lesson1.php')
-        ),
-        lesson(
-            filename('lesson2.php')
-        ),
-    }
-);
+function my_rand($student, $unit) {
+    return rand();
+}
 
-return sequence(
-    name('course'),
-    show_lesson(),
-    exercise(
-        filename('exercise.php')
+select(
+    name('Conifer/deciduous alternative'),
+    valuator('my_rand'),
+    lesson(
+        filename('conifer_decid.php')
+    ),
+    lesson(
+        filename('conifer_decid2.php')
     )
-);
+)
 }}}
 
-This uses a new control structure, '''select()'''.
-This takes a 'valuator' function (in this case, random)
+The '''select''' takes a 'valuator' function (in this case, random)
 and a set of units.
 It shows the unit for which the valuator function has the largest value.
+
+To see this in action, create a new course with short name "conifer3".
+The course document is
+[/trac/browser/trunk/bolt_examples/inc/conifer3.inc here].
+Note that the '''select''' is followed by an exercise set.
 
 == Lesson comparison ==
@@ -43 +42 @@
 After a number of students have passed through the micro-experiment,
 you may have enough data to conclude something about your lessons.
-To do this, go to the course Control Panel
-and click Lesson Compare.
+To see how this works, go to the course Control Panel and click Lesson Compare.
+
+You will be asked to choose a '''select''' unit and an '''exercise_set''' unit
+(in this case there are only one of each).
+
+Next you will be asked about "data snaphots".
+A data snapshot is a "snapshot" of the contents of your course's database,
+for the units you have selected, over some time interval.
+
+Initially, you will see "insufficient data".
+For purposes of demonstration, let's run a script that generates
+synthetic data.
+Edit ~/projects/test/html/ops/bolt_datagen.php and set
+{{{
+$clear_course_data = false;
+$generate_compare_data = true;
+$generate_map_data = false;
+}}}
+Then run the script:
+{{{
+cd ~/projects/test/html/ops
+php bolt_datagen.php
+}}}
+
+Go back and generate a new data snapshot.
+Now the lesson comparison will look like this:
+
+picture
+
+The graphs show, for each alternative lesson,
+the 90% confidence interval for the mean of the exercise score
+after that lesson was selected.
+If (as is the case here) one interval is entirely higher than another,
+it means that lesson was more effective.
+
+Now suppose you want to investigate the effect of student gender -
+e.g., whether the lessons have different effectiveness for males and females.
+Under "Break down by", select Sex, and click OK.
+You'll now see a comparison broken down by sex:
+
+picture
+
+In addition to breaking down the results by sex or age,
+you can also filter the results,
+i.e. to show only results for a particular subset of students.
+For example, if you select "Female" under "Filter by",
+and "Age" under "Break down by", you will see the results for female students,
+broken down by age.
 
 == Course maps ==