General Statistics

ZX Computing

Dennis Trebble

This program is available from WH Smiths at the price of £6.95. For this kind of money you would be right to expect a program of very high quality which met most of the demands imposed upon it without any problem. In fact, the program menu gives an idea of the capabilities - listing ten different statistical techniques! To be fair, one technique often superimposes into another, and the division between them is rather arbitrary, ie the scaler graph phases into both correlation and regression techniques. The tape is supplied with a set of adequate notes as to the running and application of the data, although it does pre-suppose a certain amount of statistical background from the user. I felt the graphics displays were adequate, but could have been improved on - in particular, the section dealing with bar charts and histograms could have made greater use of the computer's capabilities to produce more satisfying visual graphics. Obviously, the graph axes form part of a subroutine that is used extensively throughout and it is possible to lose detail concerning input data as the same axes in one operation might be using a scale from 0 to ten, whilst another might use a scale from 0 to 10,000! The section on the relationship of the mean, standard deviation and the normal curve was good - particularly the sequence of curves plotted to explore this relationship. Other methods included on the package are the Binomial Coefficient, Correlation Coefficient, Chi Squared test and Poisson Distribution. All, in some measure, were adequately explained in the printed notes accompanying the tape, but were not included as part of the on-screen instructions. The program does have its irritating side though. For example, having plotted a scatter graph, the screen is cleared almost immediately and the graph is then seen with the regression equation printed over the top. It would have been better to ask the user to clear the screen and then, instead of the regression equation, to actually let the computer plot a line through the graphed points. In summary, the publishers have tried to squeeze too much into too little, and in the course of doing so have made a number of compromises in fitting the whole package together. Is it good value for money? I think so, although you will need to consider carefully the amount of use you might give to the programs and reflect that a good calculator could manage the same tasks.