Helpdesk IBM SPSS Statistics 20 For students from Arnhem Business School | ||||||||
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Analysis A Scale VariableOn this page we deal with the Explore command of SPSS. We use it to describe quantitative data by means of numerical measures (statistics). Graphical displays for such a variable are discusses elsewhere on this site. Look at the pages on boxplots and on histograms.
The theoryWhen studying a quantitative variable (SPSS calls it a scale variable) a
frequency table is less useful. This is especially so for a continuous variable
or for a quantitative discrete variable with many different answers.
We will use Analyze > Descriptive Statistics > Explore to find the relevant statistics. Coding in SPSSIn this example we use data about the tallest buildings in the world. This data
comes from Wikipedia and was downloaded and edited in September 2011. Surely
there is an update of this data available at the moment.
The options of Explore
The first result: Statistics
To assess the symmetry or skewness of the distribution you can compare the value of median-Q1 to that of Q3-median. I.e. you compare the sizes of the left and right halves of the box in the boxplot. Note: You can see that there are several ways to calculate percentiles and quartiles and also that their outcomes may differ. Using the syntax of the SPSS Explore command you can choose six different ways to calculate percentiles and quartiles. See the page on syntax on this site if you are interested.
The first result: Stem-and-leaf display
An annotated stem-and-leaf displayWe assume that you are familiar with this display. But we have added a few
notes to show you what kind of information you find in it. Furthermore, the display clearly shows that the distribution is right skewed.
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Last modified
30-10-2012
© Jos Seegers, 2009; English version by Gé Groenewegen. |