- Java applets have been introduced to show statistical behaviour and to check pseudo-random number generators. Figure 4 shows the applet built to discover the correlation between randomly generated numbers: this applet has been downloaded from the net and improved by the members of ISHTAR [5].
The applet creates and reads a file of pseudo-random numbers generated, and plots a noise sphere of the data. Poor random number generators will show clear patterns.
It is possible to select a random number generator from four different kinds: the java random generator, the additive method, the multiplicative method and the mixed method random number generators.

Fig. 4

Another applet (see Fig. 5 on the following page), downloaded from the net and improved by the members of ISHTAR [6], shows how the sample mean tends to the population mean as the sample size increases. It is possible to test it for three different distributions: uniform, exponential and normal distributions.