In the Address Verification task, we rate a query address and a response address. First step is to rate the validity of the query address.
Query address is rated Valid when it is:
If the query address does not meet these conditions, it is rated Invalid. If you cannot prove that an address is Invalid, give it the benefit of doubt and rate it as Valid.
Query address may have small errors, misspellings, missing parts and superfluous parts (including business/POI names). This is acceptable.
Examples of Valid query addresses:
Hietapellonkatu 11, 21600 Parainen 
complete address
Hietapellonkatu 11, Lahti refers to a single location even without postal code
Hiatapellonkatu 11, 21600 Parainen misspelled, but intent is still clear
Examples of Invalid query addresses:
Hietapellonkatu 11 ambiguous, 2 possible intents
Hietapellonkatu, 21600 Parainen misses street number, not a single location
Parainen locality is not considered a clear single location
Hietapellonkatu 17, 21600 Parainen street number does not exist
To verify Finnish addresses there are many reliable sources:
https://www.posti.fi/fi/postinumerohaku
Postal authority.
Usually, an address exists if it’s listed here.
Municipality maps.
For example https://kartta.hel.fi (found by searching “Helsinki karttapalvelu”). Almost every municipality has a map portal and mostly they are very reliable.
https://kartta.paikkatietoikkuna.fi/
https://asiointi.maanmittauslaitos.fi/karttapaikka/
Both of these pages are maintained by the government, so they are quite reliable.
However, sometimes street numbers that do not exist are listed here, so it is best to use them together with the postal authority, municipality map or street view.
Street view is also a very useful tool in Finland, especially when the images are fairly recent.
In some rural areas, images might not be available, so it is best to use the other sources.
When the query is rated Invalid, the next step is to rate whether the query is reasonable or unreasonable. The Guidelines section 4. Is This a Reasonable Address? includes a very thorough explanation on this with examples.
The Country Specific Guidelines also include a section 5. Address Verification Specific Issues which is very useful for understanding common rating scenarios in Finland.
Here are some scenarios that you might encounter when rating these tasks:
Query: Metsontie 25 a, 13600 HÄMEENLINNA
Correct rating: Valid
The query includes a common misspelling.
Instead of 25a, user has typed 25 a.
Sources: https://kartta.paikkatietoikkuna.fi/ and https://www.posti.fi/fi/postinumerohaku
Query: Kalttilankatu 2, Tampere
Correct rating: Invalid – Reasonable
The query refers to an apartment complex with multiple buildings sharing the same street number. A unit letter is needed to verify one single rooftop, so this query is rated Invalid. However, this address is Reasonable, because it refers to a residential complex less than two blocks in size.
Sources: https://kartta.paikkatietoikkuna.fi/ and
https://www.posti.fi/fi/postinumerohaku
Query: Kalttilankatu, Tampere
Correct rating: Invalid – Reasonable
Query refers to a very short street without specifying a street number. As the street is short and the entire street is within eyesight, this query is Reasonable.
Sources: https://kartta.paikkatietoikkuna.fi/
Correct rating: Invalid – Unreasonable
Query refers to a sub-locality that can be broken down into more specific address components (streets), it is Unreasonable.
Sources: https://kartta.paikkatietoikkuna.fi/
If the query address is rated Invalid – Unreasonable, no more sections need to be rated.
If the query address is rated Invalid – Reasonable, the rest of the task is rated normally.
When the query is rated Valid or Invalid – Reasonable, the next step is to provide the pin coordinates of the query address. The pin should be in the middle of the building (if query refers to one building) or in the middle of the area the query refers to (in case the query refers to many buildings, a street or other zone bigger than one building). The page https://kartta.paikkatietoikkuna.fi/ is very useful when trying to identify the correct rooftops.
The main point is that in Address Verification, the Response Address is rated based on how accurately it reflects the query address. A correct response address will refer to the same unique location as the query address and be complete and well formatted. If any portion(s) of the response address are missing or incorrect, use the appropriate rating.
However, if the query address is misspelled, for example, it has a wrong postal code, the response address can be expected to have the correct postal code as verified from https://www.posti.fi/fi/postinumerohaku.
See the Guidelines section 7. Response Address Accuracy to know how to rate each address part.
In Finland, the difference between street number extension letters and unit letters can be confusing, but usually the official sources help us to reach the correct rating. Here are some rating examples:
Query: Metsurintie 4 A, 70150 KUOPIO
Response: Metsurintie 4, 70150 KUOPIO
Correct rating: Incorrect – Unit/Apt
The query specifies a unit letter and the response address does not include it. The address is an apartment complex with many buildings, so without a unit, the exact location can’t be defined. When the query address contains a unit number and the response address does not, rate:
Sources: https://kartta.paikkatietoikkuna.fi/ and
Query: Nortamonkatu 14A, 26100 RAUMA
Response: Nortamonkatu 14, 26100 RAUMA
Correct rating: Address – Correct
The query is misspelled as the street number 14A does not exist. The likely user intent is Nortamonkatu 14 A, 26100 RAUMA. Query specifies a unit letter and response address does not include it, but in this case, both addresses refer to a specific single-building location. When the query address contains a unit number and the response address does not, rate:
Sources: https://kartta.paikkatietoikkuna.fi/ and
Query: Kukuntie 10, 40800 VAAJAKOSKI
Response: Kukuntie 10, 40800 JYVÄSKYLÄ
Correct rating: Incorrect – Locality
In Finland it is very common that the postal code area is different from the larger locality. When the query address contains a small locality and the response address returns only the larger municipality/region that contains it, the rating should be Incorrect – Locality.
Sources: https://kartta.paikkatietoikkuna.fi/ and https://www.posti.fi/fi/postinumerohaku
See the Country Specific Guidelines section 5. Address Verification Specific Issues for more useful examples.
In the Address Verification task, the response address pin is a reflection of the query address. So, if the response address is not the same as the query address, the pin should still point to the location of the query address.
In Finland the official sources https://kartta.paikkatietoikkuna.fi/ and https://asiointi.maanmittauslaitos.fi/karttapaikka/ and municipality maps are very useful for finding the correct rooftops.
Recent street view images are also a great tool for locating street numbers and units within apartment buildings and complexes.
Here are some common scenarios in Finland:
Query: Pajamäentie 4 B, 00360 HELSINKI
Response: Pajamäentie 4 B, 00360 HELSINKI
We can verify from https://kartta.paikkatietoikkuna.fi/ and https://kartta.hel.fi that this address refers to a single building. This case shows how important it is to use several reliable sources before deciding your final rating. Especially the page https://kartta.paikkatietoikkuna.fi/ sometimes has slightly erroneous information. Here it would seem that street number 4 includes two buildings.
However, the municipality map shows the other building houses number 1 and street view also confirms this.
This way, our response pin should point to a specific part of the building to get a Perfect rating. If the response pin pointed to other part of the building or to the rest of the property, it would be rated Approximate.
See the Guidelines section 6. Pin Accuracy for more important instructions and practical examples regarding pin rating.