Using tier in conjunction with what can result in unexpected tier buckets?

Using tier in conjunction with dimension fill can lead to unexpected tier buckets because dimension fill can alter how values are grouped and displayed in the visualization. In Looker, tiers are often used to create groups or ranges based on numerical values, allowing for dynamic categorization and bucketization of data. However, when dimension fill is applied, it changes the structure of your data presentation based on qualitative dimensions rather than focusing purely on the numerical values used for the tier logic.

This means that if the data set contains multiple dimensions or categories, the tiering logic may not behave as anticipated, potentially leading to confusion or inaccurate representations in the resulting buckets. It's essential to carefully plan how dimension fill interacts with tiering to ensure that the visual output matches your original analytical intent.

The other options focus on different aspects of Looker’s functionality. For example, data sources have a more foundational role in data retrieval, visualization type concerns how data is represented rather than how it is categorized, and chart options involve settings that adjust aesthetic or display features without directly impacting the underlying data structure or groupings.