January 2012 Volume 15 Number 1 - Educational Technology ...

specifically, instructional approaches (F=7.28, p= 0.008) reach a statistically significant effect on the performance of
post- and retention-PSDAT. In summary, the OLSA learning group outperformed the traditional group on postperformance
of Physical Science Dependent Argumentation Test.
Multiple regression analysis
This section examines the relationship between students’ degree of conceptual change and their scientific
argumentation ability. Therefore, the stepwise regression method was used to explore whether the pre- PSDAT or
pre-PSCT test would be most important for predicting the post-PSDAT scores. Results indicated that the best single
predictor for post-PSDAT sores was the pre-PSCT, followed by pre-PSDAT scores. The standardized regression
coefficient for pre-PSCT, and pre-PSDAT were 0.41 and 0.31. Together pre-PSDAT and pre-PSCT accounted for
38.0% of the variance in post-PSDAT scores.
The Quantity and Quality of On-Line Scientific Argumentation
The experimental group’s student on-line scientific argumentation learning process was analyzed in two aspects:
nature and extent of argumentation ability and of conceptual change. The quality and quantity of students’
argumentation and conceptual change were presented in the following in order to manifest the nature and extent of
experimental group’s on-line scientific argumentation process.
Argumentation ability
All argumentation questions were designed to require 10-15 minutes for students to argue. With an average of six
students in a group, the mean frequency of arguments generated by each group in each question increased
progressively from 7.38 to 18.77 arguments during the 10-15 minutes from topic 1 to 7 (Figure 3).
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Unit1 Unit2 Unit3 Unit4 Unit5 Unit6 Unit7
Figure 3. Distribution of mean frequency of arguments generated by each groups’ students across seven units
Repeated measures of ANOVA were used to examine any increases in mean frequency of arguments from topic 1 to
topic 7. The mean frequency of arguments generated by each student in each question significantly increased from
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