Computer Resources and Terminology: A Brief Introduction

Computers have become an integral part of our lives and society; however, many people see them as being remote and difficult to understand. This article presents a brief introduction to computers and computing in an attempt to alleviate this concern. The topics discussed include the organization and hardware of computers (memory, central processor, input and output devices), data representation, computer software and programming languages, differences between computers (mainframes, minis, and micros), and computer communication and networking.     

A SIMPLE METHOD OF CALCULATING THE COEFFICIENT OF CORRELATION

Where two sets of measurements can each be grouped into below average, average and above average classifications with an equal number assigned to each of the below average and above average classifications, a 3 by 3 table can then be tabulated with frequency counts. The exact value of the product moment coefficient of correlation can then be calculated very simply by means of the formula, r = (DIFF)/2m, where DIFF is the difference between the sum of the corner numbers on the positive diagonal and the sum of the corner numbers on the negative diagonal, and m equals the number in each of the below average and above average classifications for each variable. The formula for r is applicable to negative as well as positive correlation.