Getting Started with StatCrunch (short version)

StatCrunch is a Web-based statistical software package for analyzing data. StatCrunch works on any desktop browser, such as Chrome, Firefox,
Internet Explorer or Safari. StatCrunch also works with Web browsers on smartphones or tablets running iOS, Android and other mobile operating systems. This tutorial is a quick introduction to what StatCrunch can do, including loading data, calculating basic summary statistics, constructing simple graphs, interacting with those graphs, and copying StatCrunch results into other applications.
To begin, load the Survey: Is college worth it? data set, which will be used throughout this tutorial. This particular data set contains information collected from a survey conducted at statcrunch.com. Respondents to the survey were asked if college was worth the cost with the possible answers being Yes, No or Unsure. Respondents also provided their Gender and Age. To compute two-sample results using the corresponding raw data set with individual values, see Computing hypothesis tests and confidence intervals for the difference between two means with raw data. For a tutorial that loads data from a file, see Getting started with StatCrunch.

Calculating summary statistics such as the mean and median

The Stat menu contains a number of procedures for summary statistics, tabulation, hypothesis testing, confidence intervals, regression and much more.
With this data set, consider the task of computing summary statistics such as the mean and median ages of the respondents. To accomplish this task, select the Stats > Summary Stats > Columns menu option. In the resulting dialog window, select the Age column and click Compute! to generate the table of summary statistics shown below. The mean age of respondents is shown to be roughly 29.31, and the median age of the respondents is much lower at a value of 23.

To compute separate summary statistics for each value of Gender, choose Edit under the Options menu of the summary statistics output window. In the dialog window, specify Gender under the Group by option. Click on Compute! to generate the table of summary statistics shown below summarizing the ages of respondents of each gender. The mean age of female respondents and the mean age of male respondents are both very close to 29.3. The median ages of both genders are exactly 23. For a more thorough tutorial on calculating summary statistics, see Computing summary statistics for columns.

Creating bar plots

The Graph menu contains a number of options for displaying data in a variety of formats. To summarize how respondents felt about college being worth the cost, choose the Graph > Bar Plot > With Data menu option. Choose the Worth it? column, and click Compute! to generate the bar plot shown below. In this case, this plot indicates that the overwhelming majority of respondents said that college was indeed worth the cost. For a more thorough tutorial on creating a bar plot, see Creating simple bar plots with raw data.

To break out these responses by Gender, choose Edit under the Options menu of the bar plot window to reopen the dialog window. Select Gender as the Group By column and again hit Compute!. The split bar plot shown below splits the original responses color coded by Gender. Note the majority of those who answered Yes were Female. For a more thorough tutorial on creating bar plots with grouped data, see Creating split and stacked bar plots.

Interacting with graphs

Most graphics in StatCrunch are interactive. This can be a very powerful feature. For example, to identify the females who said college was worth it, click and drag the mouse to form a rectangle which overlaps the appropriate bar as shown below. The selected data values are then highlighted in the graph, and will also be highlighted in any other graphs that are produced. The rows corresponding to the selected values are highlighted in the data table as well. Clicking the ↓ or ↑ buttons in the lower left corner of the window will scroll the data table to show the next or previous selected row. This is especially useful when a small number of rows have been selected in a large data table. Adjacent to these two arrow buttons, the value of 582 rows indicates how many rows have been selected. Turn off the highlighting by clicking on the Clear button in the lower left corner of the screen.

Saving, copying, or printing a result

Both tabular and graphical results can be saved to your My Results listing at statcrunch.com, or they can be copied, printed or downloaded. To copy the above bar plot, choose Copy under the Options menu of the bar plot window as shown below.

To finish copying the image, follow the Tip provided for your platform as shown below. After the image is copied, it can be pasted into other applications such as Microsoft Word or PowerPoint. Saving, printing, and downloading are also available under the Options menu of the bar plot window. Copying tabular results is even simpler. To copy tabular results, click in the results window and use the standard keys on that platform to copy the selection, and then use the standard paste keys to paste the results into an application such as Microsoft Word.

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