Don’t make the user provide information that the system already knows.... well, in several systems that I've worked on we "knew" several different versions of the information we were asking from the user. The question was : what did the user think right now. Truth... that's a different thing!

In that case, you could present all known versions and ask the user to simply select one instead of re-entering redundant information. Amazon, for example, remembers multiple mailing addresses and let's you select one (or enter a new address) when placing a new order.

>>Why can't the doctor's office, which already knows all of that, just print out 15 forms with all of that pre-populated?

Which brings us the principle:

Never ask a question whose answer you already know

If you know the answer already, why does the question exist on a form?

Because you don't know it for everyone.

The medical thing is an interesting cross-over though -- if a nurse walks into your hospital room because your name is on the outside and administers an injection that kills you because you were accidentally put in the wrong room, whose fault is that?

For the CS/programming side of it -- do you really know what you think you know? A smart form should let you put in house address and ZIP and look up the rest, but frequently developers think they know more than they actually do, and it's not a bad idea to have the user confirm or possibly override the information. Depends on the situation, really.

https://www.sharecare.com/health/managing-your-health-care/w...

> every time I go to a new doctor, I have to fill out 15 forms and 15 times I have to write down my ... SSN

No you do not.

Anecdotal: I always leave that field blank and have never been asked for it.

Anyone can ask you for anything, anywhere. It doesn't mean they actually need it, or that you have to give it to them.

I 100% agree.

I went to a dealer to buy a car in cash (well, a cashier's check). They had a touch-screen computer with all their forms for me to fill out. It came to a credit approval/application form, and I refused to fill it out because I wasn't opening a loan. The lady assured me it was "standard" and that it wouldn't be used for anything, because I didn't need the loan/credit. I kept refusing, and she kept insisting they only needed it because the software required it to continue. After this impasse, I stood to walk out, and she suddenly changed her tune and somehow "figured out" how to bypass the form. Classy.

Even if you pay cash, a dealer may require a credit check, however you have no obligation to provide any financial details. I think they just want to make sure your credit is good enough for some proxy that your check is good. I've also heard it's for identity purposes. Also, this all might vary by state laws, too...

> some proxy that your check is good

That's why they had a cashier's check and not a personal check.

Hmm. I wonder if shady car dealers have ever abused approval of that form. That would be interesting to find out about.

Because, considering it sounds like you bought the car outright, there's absolutely no reason for that form to need signing.

Fun fact: Car dealerships are actually considered financial institutions under FinCEN regulations. Depending on the cost of the car/cash amount, they may need your SSN for reporting purposes.

No, they still do not. Banks don't even need your SSN...

> You are not required to have a social security number to open a checking or savings account.

Source: https://www.consumerfinance.gov/ask-cfpb/can-i-get-a-checkin...

“To open a checking or savings account, the bank or credit union will need to verify your name, date of birth, address, and ID number. An ID number can be a social security number or an Individual Taxpayer Identification Number (ITIN).“

Having spent more than a few years in FinTech, I know these things can vary from company to company as companies generally are required to design their own “risk-based” policies for AML and KYC.

"can be" not "must be". Driver License number or just about anything else is legal, it's just up to the bank whether or not they want to accept it.

What do you do if they say you have to fill it out? I realize it hasn't happened in your case, but it very well can to someone else.

Tell them that I'm undocumented and paying with cash?

(I'm not undocumented, but I imagine they see that enough which is why they don't bother saying anything when I leave it blank.)

I'm pretty sure they just want your SSN for collections/credit-reporting purposes.

I don't know the law in the US, but here your medical information is private so they legally aren't allowed to give it to others

Yet it happens, while this anecdotal. I know of a married couple that broke HIPPA and actively admitted they will be doing so. One was a pharmacist one was a doctor and it involved a couple of patients and herpes. I barely knew then and I should not have heard the information. They definitely should not have shared it even as husband and wife.

Every single time I wonder, why not ask me for zip first then lookup city and state if possible.

In the 80's I made a database routine to do just this - take a zip and turn it into a city - and as well, to go the other direction. I sold it to another software company for a rather fat amount of cash, and they used it to make their production-line data entry 80% faster. In the cases where it failed and produced wrong results, it was cheaper for them to ship me the dud records for correction in the database than it was to go back to the old way.

Yet still, today, its a very rarely encountered technique. I wonder if so much has changed in the Zip+4 world to make it an efficiency sink...

I wouldn't personally trust whatever service provides this lookup to be 100% accurate, especially because there's so many weird edge cases with addresses. If the user gets it wrong, at least it's their fault and not mine.

Healthcare is an abomination. If the will existed, the situation could be radically different, but it never seems to change. "Obamacare" was just another (effective) tax increase in disguise, like adding the fees for a new thing, but never actually changing the thing itself. Sheeple one and all.

Backwards paper systems serving the moneyed interests.