Setting
The study was integrated into the fractions-
curriculum of three classes. As preparation
for the intervention-phase each teacher
designed his or her 18-lessons-course based on
common guidelines that were defined by the
teachers and the researcher. The normal extent
of such a course is about 23 lessons. To realize
the reduction of the number of lessons, the
exercise-parts of the course were shortened and
the extra time was used for a 180-minutes
exercise-period – the intervention-phase. This
phase was meant to be an individual training-
session before the class-test after the study.
So all contents of the intervention were part of
the preliminary course.
During the whole study, each class worked in its
own classroom. At first, a 30-minutes pre-test,
consisting of multiple items concerning various aspects of the introductory
fractions-course, measured the prior knowledge of the class members. Then an
introduction into the materials of the intervention-phase was given.
The following intervention setting varied slightly in the three classes. In this paper only
two of them are considered (the self-explanation prompt class and the training class, 56
subjects), the third class worked without animated worked-out examples. Students of
the prompt class received worked-out examples accompanied with self-explanation
prompts. No prompts were presented to the students of the training class. They passed a
self-explanation training during the introduction before the intervention phase instead.
In the first 90 minutes of the intervention-phase the students dealt with three selected
animated worked-out-examples and two incomplete examples. In addition, they
completed a self-assessment questionnaire and worked individually about twenty
minutes. That means they could decide on their own which tasks or examples they
wanted to work with. During the second 90 minutes the students concentrated on two
further selected examples and could use the rest of that time for individual training.
The same instructor, who was unknown to the students, conducted the intervention
phase of each class. To quantify the learning outcomes, a post-test – designed
matchable to the pre-test – was carried out.
Materials
During the intervention-phase the students of the two classes worked with a computer-
supported learning environment and a workbook. The computer environment
provides 18 different interactive animated worked-out examples related to the sections
of the fractions course. The workbook contains the self-assessment questionnaire,
instructions for the animated worked-out examples (accompanied by self-explanation
prompts in the self-explanation class), incomplete examples and tasks.