Statistics and Graphics Functions

Transcription

1 Statistics and Graphics Functions

2 Statistics and Graphics Functions Frequency Tables and Diagrams for Variables With the help of the Statistics and Graphics module, MAXQDA can create frequency tables and corresponding diagrams for code variables as well as document variables. These functions can be accessed in the following ways: from the menu Variables > Statistic of document variables and Statistic of code variables, or with the Statistic of document variables button on the MAXQDA standard toolbar, The split Choose variables window is displayed below: On the left side, all existing variables are listed; on the right, the selected variables. The arrow buttons in the middle allow you to transfer variables from one window to the other, i.e. for selection for analysis or removal from the selection list. To select multiple variables, hold down the Shift (ñ), Ctrl (Windows) or cmd (Mac) key. 1

3 Statistics and Graphics: Choose Variables Note: System variables that are created and managed by MAXQDA are marked in red; codes that have been transformed into variables are marked in green. Both lists can be alphabetized by clicking on the column headers. By selecting Only activated documents you can limit the analysis to currently activated documents, for example the transcripts of selected interviewees. The corresponding option Only activated codes is also available. Tip: The statistics functions for variables can also be accessed directly with the button in the List of document variables and List of code variables. MAXQDA then begins the statistical analysis for only the selected variables, then considers all documents or codes. When you click OK MAXQDA will begin the statistical evaluation and display the results as frequency tables and charts. The results window displays the results of the first selection of variables in a table. The Frequency column shows how many of the analyzed documents contain the variable value in question. Frequency Table Tip: Click on the column headers of the first two columns in order to modify the order of the table rows. For example, you can sort the frequency of categories in ascending or descending order. The first column lists the various categories of the variable; the second column lists the absolute frequency; and the third lists the corresponding percentages. The fourth column shows percentages based on valid values, meaning missing values are excluded. If there are no missing values among the variables in question, the 2

4 percentages of the third and fourth columns will be identical. You can customize the order of the rows within the table by clicking on the column header of the first and second columns. For example, you can sort the table in ascending or descending order in regards to categorical frequency. The results window has a toolbar at the top. From here you can: Call up the chart view by clicking the button Flip forwards or backwards between variables Print results, or Export results as an Excel file Charts When you switch to the chart view with the button, a bar chart of the variables in question appears in the place of the table view. Horizontal bar chart of the document variable Age Note: The order of chart segments is determined by the order of the rows in the table, and can be modified accordingly. You will see two toolbars at the top of this window. The upper toolbar is the same as the frequency table, and you can switch at any time to the table view. On the right side of the toolbar you will see three buttons, with which you can choose between pie chart, horizontal and vertical bar chart. The chart can be customized using the options in the lower toolbar 3

5 Display labels hide or show categorical labels of bar and pie charts on the x-axis. Display data values hide or show the data label, meaning frequency of variable values or subcodes. Display percentages show relative, rather than absolute frequencies. Display missing values hide or show missing values category. Display legend hide or show the legend, which is switched off by default in bar charts. Display scale hide or show the scale axis in bar charts. Display title hide or show diagram title. Display text hide or show textual description of diagram. One color use the same color for all pie or bar chart segments. Color gradient add color gradient to pie or bar chart segments Change color scheme opens window for color scheme selection. Customizing Chart Captions, Color and Font Sizes When creating charts, MAXQDA sets an initial color scheme. To customize your charts, double-click on the selected segment and choose your desired color. Click on the Change color scheme button to select between three preset color schemes. Double-click on the title or description to customize content. Formatting, such as font, font size and font style, can be changed via the dialog window that appears when you right-click on the title, description or another label. 4

6 Modify color and font size in charts Print and Export Charts Like frequency tables, charts can be printed and exported. Charts will be exported in PNG format, or as vector graphics in SVG format. Missing Values in Frequency Tables and Charts MAXQDA will treat the following as missing variable values: For numerical and text variables, values set as Missing values in the List of variables will be treated as missing. For text variables, blank fields will also be treated as missing. Descriptive Statistics When evaluating numerical variables the Descriptive statistics symbol is appears in in frequency tables. Clicking on the icon produces an output of the usual parameters such including mean value and variance. 5