positive_score_impact does not work with rank_features field

[KylePiira]

So the rank_feature field has a positive_score_impact parameter to make it have a negative correlation with the score. However, this parameter does not work on rank_features fields.
When I try it, I get the following error: unknown parameter [positive_score_impact] on mapper [rank_features] of type [rank_features]

[elasticmachine]

Pinging @elastic/es-search (Team:Search)

[mayya-sharipova]

@KylePiira Thank you for submitting the issue. We can add positive_score_impact parameter to rank_features type as well, but if used it will be applied to all sub-features of this rank_features.

Will this address your use case?
I am also interested to learn more about your use case of using positive_score_impact=false with rank_features.

[KylePiira]

Hi @mayya-sharipova, yes that would address my use case. I'm using rank_features where the key is a user ID and the value is a rating that a user has given to a particular document. When a user performs a search I want to boost documents that they have rated highly in the results (currently possible with rank_feature). However, users can also give negative ratings to documents and I would like to negatively boost those in the results.
So for a given document you might have:

{
	"title": "...",
	"body": "...",
	"positive_ratings": {
		"1": 5,
		"3": 2,
		"7": 3
	},
	"negative_ratings": {
		"6": 4,
		"2": 8
	}
}

Where positive_ratings is a rank_features with positive_score_impact=true and negative_ratings is a rank_features with positive_score_impact=false. Users 1, 3, and 7 have rated the document with scores of 5, 2, and 3 respectively. Users 6 and 2 have rated the document with scores of -4 and -8 respectively.

[mayya-sharipova]

@KylePiira Thanks for sharing your use case; it was very useful. I was also thinking along the same lines.