Jorma Sajaniemi
Many kinds of supporting material are needed for lectures: lecture notes, presentation material, and guidance material for the lecturer. Current computer-aided presentation systems do not support easy preparation and maintenance of these interwoven materials.
SHOW is a computer-based classroom presentation system that support the maintenance of three levels of teaching material within a single source. Figure 1 gives a schematic description of the levels.
Figure 1: Three-level nature of teaching materials.
SHOW includes a program to produce the various versions as well as a program to present the presentation version to students. Features of the presentation program include:
Figure 2 gives an example of the look of the original text, in this case a description of C++ constructors in an object-oriented programming course. Presentation level material is marked in the original text by enclosing it with "<<" at the beginning and ">>" at the end. Directions intended for the teacher only, start with a "<" at the end of a line and end with ">>".
A C++ constructor may contain the following:
- base class constructor call<<
or several calls in the case of multiple inheritance>>
- member initializer list
- body, i.e., a compound statement <
------------------------------------------------------
Re-show the base class Performer first
so that students will remember it !
------------------------------------------------------
>> <<
class Singer : public Performer {
private:
char register; int highest;
public:
Singer(char *name, char range, int tone)
: Performer(name), register(range), highest(tone)
{kind = new char [MAXKINDLENGTH]; singertype(kind,range);}
char getRegister() {return register;}
}; >>
The system generates two (public) constructors for each class:
- a default constructor with no arguments
- a copy constructor with an object to be copied as
its sole argument
Figure 2. Text with three levels.
Figure 3 shows the learners' version, i.e., lecture notes consisting of the base text only. The system allows the teacher to discriminate parts of the text by applying different colors to text selections during the presentation. In Figure 4 three colors are used to emphasize the connections between the verbal list of C++ constructor constituents and their occurrence in the example program.
A C++ constructor may contain the following:
- base class constructor call
- member initializer list
- body, i.e., a compound statement
The system generates two (public) constructors for each class:
- a default constructor with no arguments
- a copy constructor with an object to be copied as
its sole argument
Figure 3. Lecture notes version of the text of Figure 2.
Figure 4. Outlook of a presentation in the Windows version.
Fonts and colors used for texts of different levels as well as the background color can be freely changed during presentation. Figure 5 shows the windows for font and color selection (in the style of the UNIX/Linux version of the system), as well as the Edit menu that is torn off the menu bar.
Figure 5. Setting fonts and colors in the UNIX/Linux version.
HTML-based SHOW is a variant of SHOW that relies on HTML editors for preparing materials and HTML browsers for presentation and printing. Thus HTML-based SHOW takes only care of creating the various versions from the single source. As a result, the special support of standard SHOW for presentations (text discrimination by color, ...) is lost. On the other hand, HTML browsers have better support for, e.g., figures.