Statistics
Millar
Biology statistics made simple using Excel
Biology statistics made simple using Excel
Neil Millar
Spreadsheet programs such as Microsoft Excel can transform the use of statistics in A-level science
Statistics is an area that most A-level biology students (and their teachers!) find difficult. The formulae are often complicated, the calculations tedious, degrees of freedom mysterious, and probability tables confusing. But in fact students need no longer grapple with any of these. In real life, biologists and statisticians rarely use calculation and tables these days, but instead use statistical packages such as Minitab or SPSS. But it isn’t even necessary to buy an expensive statistics package, since spreadsheet software such as Excel has most of the common statistical tests built-in. When using statistics, the first hurdle is to decide which statistical test to use. Figure 1 (overleaf) is a flow chart showing when to use the various tests described in this article. There are many other possible statistical tests, but this flow chart should be more than sufficient for A-level biology students. It briefly summarises the Excel formulae and how to interpret the results, so it can be used as a handy guide on its own once the student is familiar with the tests. This flow chart should be used when designing an experiment, not after the experiment is complete. This will ensure that the correct kind of data are collected so that the statistical test will be valid. The rest of the article describes in detail how to carry out these tests using Excel and how to interpret the results. It is divided into five sections:
ABSTRACT Modern spreadsheet software, such as Microsoft Excel, can transform the use of statistics in biology. Instead of being difficult to do and to interpret, statistical tests become simple to do and much easier to interpret. This article describes when and how to carry out many of the most common tests (including mean, standard deviation,
Biology statistics made simple using Excel
Biology statistics made simple using Excel
Neil Millar
Spreadsheet programs such as Microsoft Excel can transform the use of statistics in A-level science
Statistics is an area that most A-level biology students (and their teachers!) find difficult. The formulae are often complicated, the calculations tedious, degrees of freedom mysterious, and probability tables confusing. But in fact students need no longer grapple with any of these. In real life, biologists and statisticians rarely use calculation and tables these days, but instead use statistical packages such as Minitab or SPSS. But it isn’t even necessary to buy an expensive statistics package, since spreadsheet software such as Excel has most of the common statistical tests built-in. When using statistics, the first hurdle is to decide which statistical test to use. Figure 1 (overleaf) is a flow chart showing when to use the various tests described in this article. There are many other possible statistical tests, but this flow chart should be more than sufficient for A-level biology students. It briefly summarises the Excel formulae and how to interpret the results, so it can be used as a handy guide on its own once the student is familiar with the tests. This flow chart should be used when designing an experiment, not after the experiment is complete. This will ensure that the correct kind of data are collected so that the statistical test will be valid. The rest of the article describes in detail how to carry out these tests using Excel and how to interpret the results. It is divided into five sections:
ABSTRACT Modern spreadsheet software, such as Microsoft Excel, can transform the use of statistics in biology. Instead of being difficult to do and to interpret, statistical tests become simple to do and much easier to interpret. This article describes when and how to carry out many of the most common tests (including mean, standard deviation,