Clicking on any Visibility Score or the question mark next to it, shows a detailed explanation of what affected its value in the selected timeframe.
Unlike the performance-related changes that are reflected in the Visibility Score change (+/- %) values shown in the top-stats or the groups sidebar, the non-performance ones only affect its graph.
These are caused by the keyword list being modified and not the website performing differently. Below, we can see a performance-related change of +1.4%, while the base-level (of the chart) changed by -0.5%:
Considering that the Visibility Score is an impression share, any changes in the total search volume of the keywords list would be affecting its value, thus the need to separate them from the performance-related changes.
Since these changes are only visible on charts, automatic annotations are placed on the graph when keywords have been added / deleted or there have been AdWords keyword re-aggregations:
To improve the transparency, we’ve developed a feature that allows you to see all of the changes that happened in the keyword list, once you click on "See details". It also shows their impact on the entire search volume of the list and, therefore, on the Visibility Score graphs:
Want to take things further?
We've already gathered some tips on how to interpret these changes in the Visibility Score.