Can I boost or bury results with a Rule using less-than, more-than or equal-to a numeric value?

Currently, there is no way to achieve this without adding an attribute to your records. 

Why?

Boosting or burying records relies on optionalFilters which do not support numeric comparisons. This means you cannot use conditions such as greater than (<), equal to (=) or less than (<) with numeric values. 

This also means, when using the Visual Editor, it is not possible to use numeric attributes (ie. attributes that hold numeric values) when choosing which category to boost.

Is there a  workaround?

Sure! You can modify your data in either of the following ways:

1. Create a boolean attribute in your records that updates to true when a record meets the criteria for boosting.
2. Add values to an attribute such as _tags when the record meets the criteria.

You can then apply optionalFilters to these either of these attributes or select them as the category for boosting.

Examples

If you were originally trying to boost t-shirts with price < $20 (price < 20), you could:

• add a boolean attribute cheaper_shirts to each of these records
• use cheaper_shirts:true in your Rule to boost them

This article gives an example solution for boosting best-selling items: https://support.algolia.com/hc/en-us/articles/5851934555025