Creates a Stacked Column Chart automatically annotated with statistical significance for differences between two tables. It is the visualization option used along with the Table of Differences feature.
Technical details
Description
This is typically used in tracker studies where one would show how the results have changed over time.
Data/Inputs
The following is an explanation of the options available in the Object Inspector for this specific visualization. Refer to Visualization Options for general chart formatting options.
INPUTS
Output select the type of output to display from this analysis. It can one of Table of Differences or Stacked Column Chart with Statistical Significance.
Table 1 A Q Table containing the data to be plotted. The size of the bars in the column chart are determined by the primary statistic in the input table, and the chart will also show arrows indicating which values are statistically significant in the same way as the Q Table. If Table 1 contains "Column Comparisons", then up-arrows indicating that values are significantly increased relative to the same values in other columns (but the same row) are shown. Otherwise, if Table 1 contains the z-Statistics, then up and down arrows reflecting the arrows in the table are shown. If Table 2 is provided, however, the difference of the two tables is shown instead of using the cell statistics in Table 1.
Table 2 If a second table is provided then, it is expected to have the same primary statistics and row/column names as Table 1, as well as the appropriate sample size and standard error cell statistics. A t-Test will be performed comparing Table 1 and Table 2 and arrows reflecting the z-Statistics from this test is shown in the same way as Tables - Table of Differences. The size of the bars in the column chart will reflect the primary statistic in Table 2.
Number of categories below axis An integer, indicating the number of categories to be shown below the y = 0 (values axis zero) line.
Column totals - above If selected, the sum of the categories above values axis zero line is shown above each bar. If column totals are shown then font controls can be found in the CHART > DATA LABELS group. The format of the column totals will be the same as the format of the data labels.
Column totals - below If selected, the sum of the categories below values axis zero line is shown below each bar. If column totals are shown then font controls can be found in the CHART > DATA LABELS group.
APPEARANCE
Gap between bars Specify the amount of space between bars as proportion of the available space. Values can range from 0 (no gaps) to 0.99 (bars are shown as lines).
Vertically center data labels If selected, data labels in stacked column charts are placed in the middle of the column; the alternative is to have the data labels placed at the top of the column.
ANNOTATION
Arrow colors When the chart is showing z-Statistics or comparing the difference between two tables, the two color pickers are shown to control the color of arrows indicating a significant increase or decrease. However, for if the chart is shown Column Comparisons, then a color palette selected, with a color for each column.
Arrow size The size of the arrows used to show statistical significance in pixels.
Arrow offset The position of the arrows as a proportion of the space between bars. This automatically based on the Gap between bars, however, it is possible to move the arrows closer to the bars (left) by reducing the offset or further away (right) by increasing the offset. If the arrows overlap with the bars (especially likely if there many column comparisons in the table), it better to increase the gap between bars, or increase the total width of the widget.
DIFFERENCE LABELS
This group of controls is only shown if both Table 1 and Table 2 are provided as the input data. They control the appearance of the labels showing the difference between the primary statistic of Table 1 and Table 2.
Append differences to data label Option to show difference labels next to the data labels inside the bars instead of to the right of the bars (default). Note if this option is selected, then difference labels are only shown when data labels are. Difference labels will be hidden when data labels are not shown, or if the primary statistic is smaller than the minimum threshold.
LEGEND
Show legend for arrows If selected, a legend for the arrows used to indicate statistical significance is shown in the footer of the text. More controls to adjust the font are available in TITLE > Footer font family.
Separate legend using one of 'New line', 'Centered dot', 'Space'. The character used to separate the legend for each type of arrow in the footer.
Output
The tables below produce the graph underneath:
You can also use column comparisons with this feature:
Method
- In Displayr: How to Create a Stacked Column Chart with Statistical Significance
- In Q: Create > Charts > Visualization > Column > Stacked Column with Custom Tests