# How to calculate the overall association score?

Hello Open Targets Platform,

I am interested in the overall association score between myeloproliferative disorder (EFO: EFO_0004251) and JAK2 (Ensembl: ENSG00000096968). The overall score shown on the web page is 0.87. How to calculate this score?

Step 1: Obtain source score

Step 2: Weight those data source score by Data source weights.
I have some problem with the mapping with “datasourceId” and the " Data source"
on the above website. For example, does “ot_genetics_portal” belong to “Others” on the web?
Do “eva” and “eva_somatic” belong to “Others” as well?

Step 3: Sort those weighted data source score in a descending order.

Step 4: Do the harmonic sum, that is, S = S1/1^2 + S2/2^2 + S3/3^2 + …

Step 5: Calculate the normalized factor: NS = 1/1^2 + … + 1/11^2 = 1.558

Step 6: Normalized score = S/NS is not equal to 0.87

My question is which steps are wrong for calculating the overall association score.

Best,
Charlie

Hi @charlie,