Informatica

Teaching of computer programming by electronic mail has been held in Lithuanian schools since 1992. School students of upper grades (8–12) took part in the experiments. The experiments showed that students cope better with first stages of programming (specifying the problem, etc.) than with the last ones (programming, debugging). The analysis of programming products (made by their peers) by students themselves may be expected to be an important component of learning and teaching.

The results of investigation of computer programs written by school students during the 6th International Olympiad in Informatics are presented. Pascal program texts are analyzed on the lexical level. A certain relationship is indicated between program correctness and usage of some programming constructs as well as readability of the program text. The results are discussed from the standpoint of programming teaching.

The paper deals with a simple model of the competition of two queuing systems, providing the same service. Each system may vary its service price and its service rate. The customers choose the system with less total service price, that depends on the waiting time and on the service price. The possibility for the existence of equilibrium is investigated. Simple cases are investigated analytically. It is shown that the Nash equilibrium exists in special cases only. A modification of the Stakelberg equilibrium is proposed as a model of competition with a prognosis. This prognosis helps form more stable prices and more stable strategies of competitors. The case of social economics is investigated, too. The dynamics of the competition of more realistic stochastic queuing systems is investigated by Monte Carlo simulation. The simulative analysis is realized by means of a rule-based simulation system.

A classification of teaching forms is introduced. One-to-many (group) distance teaching forms are discussed with respect to the means, which are used in the programming teaching process. The role and the possibilities of electronic mail in this process is discussed. The experience of Lithuanian Young Programmers' School by Correspondence is referred to.

The role of an interface between an algorithm and its environment for school students is discussed. The motivation of the use of Pascal functions and procedures instead of commonly used programs in the first lessons of programming is presented. The main features of an interpreter of algorithms (Pascal functions and procedures) implemented on school computer are presented.