Unsure of score in Elasticsearch

Question

I am using ElasticSearch in a seach engine that I have built. I am unsure about the scoring in Elasticsearch. See my code below

for(let i=0; i<lens; i++){
                        source = data[i]._source
                        src = source.src
                        alt = source.alt
                        desc = source.desc
                        score = data[i]._score
                        this.results.push({src: src, alt: alt, desc: desc, score: score})

Now this does bring back a result, but they are like 7.764. What does this value mean. Is it 7.764% ??

Answer 1

Elasticsearch uses the BM25 algorithm for scoring, and its not the % which you are guessing.

Apart from BM25 reading, you can also use the explain API which explains how the score of each matching document is calculated.