Getting the closest string match

Question

I need a way to compare multiple strings to a test string and return the string that closely resembles it:

TEST STRING: THE BROWN FOX JUMPED OVER THE RED COW         


        

Answer 1

There is one more similarity measure which I once implemented in our system and was giving satisfactory results :-

Use Case

There is a user query which needs to be matched against a set of documents.

Algorithm

1. Extract keywords from the user query (relevant POS TAGS - Noun, Proper noun).
2. Now calculate score based on below formula for measuring similarity between user query and given document.

For every keyword extracted from user query :-

• Start searching the document for given word and for every subsequent occurrence of that word in the document decrease the rewarded points.

In essence, if first keyword appears 4 times in the document, the score will be calculated as :-

• first occurrence will fetch '1' point.
• Second occurrence will add 1/2 to calculated score
• Third occurrence would add 1/3 to total
• Fourth occurrence gets 1/4

Total similarity score = 1 + 1/2 + 1/3 + 1/4 = 2.083

Similarly, we calculate it for other keywords in user query.

Finally, the total score will represent the extent of similarity between user query and given document.