How our rating system works

Garage Finder’s rating calculation is performed based on two components: (1) Surveys completed by users to be made a service garage and (2) Penalties due to slow response to queries sent by Garage Finder’s system.

The first step in the rating calculation process is the calculation of the set of values for component (1). That is:

A1 = total number of surveys concluded for all garages

B1 = average value of the results of concluded surveys of all garages that have been surveyed at least once

C1 = total number of rated garages

The second step in the rating calculation process is the calculation of the set of values for component (2). For this component of the rating system, we consider that penalties due to slow response to queries sent by Garage Finder’s system is not a factor as important as (1) customer surveys. For that reason, we use a lower weight (K) for it.

That is:

K = weight for penalties due to slow response to queries sent by Garage Finder’s system.

K has a value of 0.1 (zero point one)

With this factor, we calculate the values for​​ penalties due to slow response to queries sent by Garage Finder’s system:

A2 = total number of penalties for all garages x K

B2 = average value of penalties of all garages that have one penalty at least x K

C2 = total number of garages with at least one penalty x K

The third step, is to combine these two factors using the following formula :

Total number of events (A) for all garages = A1 + A2

Average values of events (B) = (B1 x ((A1 / A)) + (B2 x (A2 / A)))

Total number of garages involved in events ( C ) = C1 + C2

The fourth step, is to apply the following formula based on the Bayesian Estimation1:

Result of rating = ( ( b3 x b4 ) + b2 ) / ( b1 + b3 )

Where:

b1 = Number of surveys for a given garage + (Number of penalties of a garage x K)

b2 = Sum of values of survey results for a given garage + ( Sum of values of penalties for a given garage x K)

b3 = Total number of events (A) / Total number of garages involved in events ( C )

b4 = Average values of events (B)

About penalties

We have determined the following penalty rules for garages:

For each garage appointment request answered by the garage after the reminding alert, the garage will have one penalty of -2 points.For each rejected appointment, the garage will have one penalty of -3 points .

1  https://districtdatalabs.silvrback.com/computing-a-bayesian-estimate-of-star-rating-means