The invention of electronic spreadsheets along with word processing software and databases unquestionably was a major factor in convincing people of the worth of microcomputers in the early years after Apple and IBM began marketing personal computers. Since that time, the constantly increasing versatility and wider applications of spreadsheet software have made it into a product that seems almost indispensable to business and personal users. Spreadsheets are now a standard part of office suite packages.
Dan Bricklin and Bob Frankson invented the first practical spreadsheet for microcomputers. They called it VisiCalc. It was released for the Apple II computer in 1979. Prior to this, spreadsheets had to be manually recalculated each time one cell was changed. With Visicalc, work that might take a week could be done in minutes. Several years after VisiCalc's release, the inventors sold the program to Lotus Development Corporation, who renamed it Lotus 1-2-3 and upgraded the software to run on an IBM-PC or compatible computer.
VisiCalc was one of the first "killer" applications for microcomputers. It became a best-seller and led not only to more involved and better spreadsheets, but also a valid microcomputer selling point for the business community. While financial calculator programs existed before VisiCalc, it qualifies as the first electronic spreadsheet because it mimicked the look and feel of paper spreadsheets but was far more sophisticated and speedy. The microcomputer used an interface that was truly WYSIWYG---What You See Is What You Get---and intuitive in its use.
Spreadsheets can do more than perform simple arithmetic calculations. A spreadsheet can translate complicated data and reports into a combination of numbers and graphs. Modern versions include an extensive list of financial calculators, such as interest calculations, loan amortisation, even calculations for Treasury bill rates. Statistical functions from common calculations (Chi Square, Pearson Coefficient of Correlation and Standard Deviation) to abstruse functions like the Hypergeometric Distribution and the Poisson distribution return needed values with no pain. There are at least 100 of these formulas included in contemporary spreadsheets.
Spreadsheets can function as basic databases. By inserting data and number in different columns, the results can be sorted, searched or filtered. What-if analysis can run using data from cells in a spreadsheet. There are mathematical and trigonometric functions as well. A user can create a simplified mailing list in a spreadsheet by entering names and addresses in individual columns. There are even word processing features offering control over fonts, bold or italic typeface, size, colour and page formatting.
Because of the complexity of how a spreadsheet works and the potential to develop complicated and interrelated calculations, the potential for error increases exponentially with the size of the spreadsheet. Audit controls are limited and often what is possible in this area is underutilised. All too often not enough planning goes into the development of spreadsheets, particularly when designed for other users. Because it is so easy to change values in the spreadsheet, easy mistakes have unintended consequences.