Even though a software program is automated there can still be mistakes as it is quite easy to enter incorrect information. Of course if the information entered is incorrect then the program will also give you incorrect information. Because even a small error will make a huge difference to a chart, it is very important to check your information. Therefore it is advisable to know basic mapping techniques and how you would calculate a chart manually, so that you can check that the chart produced by the astrology software is correct.