Page 494 - Canadian BC Science 9

Graphing on a Computer
Computers are a useful tool for graph preparation for the following reasons.
1. Data need only be entered once. As many
graphs as you need can then be prepared
without any more data entry.
2. Once the data are entered, you can use the
computer to manipulate them. You can change the scale, zoom in on important parts of the graph, graph different parts of the data in different ways, and so on—all without doing any calculations!
3. Computers prepare graphs far more quickly than people working carefully.
4. Computers can be hooked up to sensors (thermometers, timers, etc.), so you do not need to read instruments and enter data by hand, with all the resulting possibilities for error. The computer can display the readings on a graph as data are collected (in “real” time), so you can quickly get a picture of how your experiment is going.
5. Errors can be corrected much more easily when working with a computer. Just correct the error and print again.
6. Computer graphs can be easily inserted into written lab reports, magazine articles, or Internet pages. It is possible to scan hand-drawn graphs into a computer, but it is not easy to do it well, and the resulting files are very large.
7. Once data have been entered into a computer, the computer can determine a line of best fit and a mathematical equation that describes the line. This line can help you to discover patterns in your data and make predictions to test your inferences.
476 MHR • Science Skill 5