Research in the field of multimedia has yielded principles for the design of effective multimedia instructional messages including Mayer's principles regarding voice. According to the voice principle, students learn more deeply when the narration in a multimedia lesson is spoken by a native voice rather than a non-native voice. The generalizability of the voice principle has been demonstrated when applied to multimedia users who are native speakers of the language used in narration. However, three out of four English users are non-native speakers of English, and the vast majority of verbal exchanges in English do not involve any native speakers of the language at all. By focusing on non-native users, the results of this study should clarify the applicability of the voice principle to a broader target audience. The study investigated whether the accent of the narrator in a multimedia tutorial affected participants' learning and attitudes toward the narrator. The independent variable of the study was narrator's accent with two levels: native accent and non-native shared accent. The dependent variables of the study were participants' learning and their attitudes toward the narrators. Sixty-five Chinese participants at a Midwestern university in the United States were randomly assigned to one of two groups in this experimental design. Data to test the dependent variables were collected through a learning achievement test and an attitude survey. Data analyses revealed that there was no significant difference in overall learning and recall level learning between the two accent groups. However, the group who heard the narration spoken with the native American English accent had significantly more positive attitudes toward their respective narrator than the group who heard the narration spoken with a non-native shared Chinese accent. The study qualifies the voice principle by establishing the limits of its generalizability to non-native English speakers. The study suggests to instructional designers that the use of a non-native shared accent should not affect students' learning negatively although it may affect their attitudes toward the speakers. In addition, the study helps assure non-native instructors that they can record their own voices to use in multimedia instruction as their non-native students will learn as effectively as with a native English accent.

By analyzing electronical tools, online applications and tutorials from Czech Republic and abroad I have come to the conclusion that it is necessary to create a flexible educational instrument which includes digitized chemical experiments for general chemistry. Following the analysis of present databases, CD ROMs and VHS containing pictured experiments I found out that a lot of spectacular experiments with pyrotechnical components have not been shooted at all or not in the range of "greater" chemicals quantity. The chosen programming language, in which FMDP was written, proved to be most efficient. This choice emerged from a discussion with programmers and was motivated in particular by larger possibilities of C# than HTML have. In addition to it the modification of the FMDP content is easy. The teachers with minimum of the PC-literacy can make any changes in FMDP, alternate any of its parts and adapt them for various internal and external conditions of education. With regard to the interview having found the needs of learners I filmed and digitized especially such experiments that present the chemical reactions accompanied by the rise of a smoke, light emission, explosion and a surprising turn of colours. On the basis of the statistical evaluation of statistical data containing marks achieved by...