Visualizing Data with Tableau

Formatting

We will now apply several formatting options to make the scatter plot cleaner and easier to use. We will format the points, remove unnecessary grid lines, modify the tooltip, and edit our axes.

Learning Objectives

  • Format scatter plot points.
  • Format chart axes.

Data Points

The circle outlines we are currently using for our data points feel very cluttered to me. Changing them to a simpler shape would make it easier to examine the visualization and understand what is happening. Something the outlines do very well, however, is indicate where there is a lot of point overlap. In the center the overlap is so extreme that we basically have a solid blue blob. If we use a simpler shape, like solid circles, such a blob would not have the same meaning, since we could achieve it with far fewer mods. We will mitigate this slightly by making our points partially transparent. That way we will see darker areas where there is overlap.

  1. Click on the Shape box in the Marks shelf.
  2. Choose your preferred shape. I picked the solid circle, as I find it a lot cleaner than the circle outline, but you can pick whatever you like best. The Shape popup menu
  3. Click on the Color box in the Marks shelf. There are options for color, opacity, and effects.
  4. Change the opacity to 40%. At this level of opacity, it is still easy to show single data points like SkyUI while indicating areas of considerable overlap. The Color popup menu

Grid Lines

As with the bar chart, we have unnecessary grid lines - chartjunk. We will remove these.

  1. Right click any blank space on the worksheet and choose Format....
  2. Click on the Lines symbol near the top of the Format section that replaces the Data sidebar.
  3. Make sure the Sheet tab is selected, as opposed to the Rows or Columns tabs.
  4. Set Grid Lines, Zero Lines, Axis Rulers, and Axis Ticks to None. Removing unnecessary lines

    Note that this time we do not need to switch to the Columns tab to change Grid Lines there. If you check, you will see that Grid Lines is already set to None. It would seem that the issue we had with bar charts is not an issue for scatter plots.

  5. Click the X at the top right of Format Lines to return to the Data sidebar.

Tooltip

The biggest issue with our tooltip is that it currently displays Mod ID in addition to endorsements and total downloads. Although Mod ID is useful for telling Tableau how to group and plot our data, it is not a particularly meaningful value, either to us or our audience. Mod name would be much more informative and interesting.

  1. Locate Name from the Data sidebar and drag it onto the Tooltip box on the Marks shelf.
  2. Click on the Tooltip box and remove the line displaying the Mod ID. There is no reason to have this cluttering out tooltip when it is not useful.
  3. (Optional) Remove the label for Name and center the value, as we did with Country in the map tooltip. Tooltip text. <ATTR(Name)>, Endorsements: <SUM(Endorsements)>, Total Downloads: <SUM(Total Downloads)>
  4. Click OK.

Axes

Finally, we will make a few edits to the axes. There are two main changes worth making. The first is making the range fixed. The Endorsements range (y-axis) currently goes up to somewhere between 700,000 and 800,000, but if we filtered the dataset, perhaps showing only mods with the category Books and Scrolls, this range would adjust to better fit that limited dataset. While this can be quite useful, it can also be confusing. If a viewer didn't notice how the range changed, it would look like mods from Books and Scrolls had more endorsements (and total downloads) than they actually did. Keeping the range fixed will eliminate this problem. It does mean we may be left with extra whitespace depending on what subset of mods we are looking at, but I find this a reasonable price to pay.

The other change we will make is to the axis ticks themselves. We have a tick mark every 100,000 endorsements, making for a fairly busy axis. These extra tick marks are not really helping us or our viewers, however. As long as I have a general idea of the range, that is good enough to estimate what is happening in the scatter plot. If I want to know exactly how many endorsements or downloads a mod has, I can hover over the data point and examine the tooltip. We will therefore set larger gaps between tick marks.

Endorsements (y-axis)

  1. Right click on the y-axis (Endorsements) and choose Edit Axis.... Edit y-axis
  2. In the General tab, set the Range to Fixed. There is no need to change the default values. Editing y-axis: General
  3. Switch to the Tick Marks tab.
  4. Set the Major Tick Marks to Fixed. Here we are less concerned about having them change on us (since the range will not change), but we cannot define the tick interval without choosing this setting.
  5. Change the tick interval to 250,000. Editing y-axis: Tick Marks
  6. Click the "X" symbol at the top right of the menu to dismiss it.

Total Downloads (x-axis)

  1. Right click on the x-axis (Total Downloads) and choose Edit Axis....
  2. On the General tab, set the Range to Fixed. There is no need to change the default values here either. Editing x-axis: General
  3. Switch to the Tick Marks tab and set Major Tick Marks to Fixed. There is no need to change the tick interval this time, since it defaults to 10 million. Editing x-axis: Tick Marks
  4. Close the window.

Finished Plot

The finished, formatted scatter plot

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