In a Nutshell :
The Product Improvement program is related to OEM and the Feedback is related to Windows OS.
The long story :
The Product Improvement Program seems to be the continuation of Nokia Improvement program.
All the official links to Nokia Improvement program were removed. However I was able to find articles on knowyourmobile.com, geeksquad and ee.co.uk that describe Nokia Improvement program as a part of setting up a new Lumia.
The purpose of Nokia Improvement Program as quoted in this article is,
The next page will allow you to opt in or out of Nokia's ‘Improvement
Program,' essentially choosing whether or not to allow the phone to
feed information to Nokia which it can use to develop new or existing
There is no official reference that older Nokia improvement program is the current Product improvement program. However it is safe to assume that they are same since,
- Microsoft bought Nokia.
The older links to Nokia Improvement program such as below ones from search results open Microsoft's privacy statement.
Their visuals are similar.
So, Microsoft has two option to collect telemetry data as one is related to OEM and the other one is related to OS. It is worthy to note that Product Improvement Program was also present in my Asha smartphone. It appears what @Thomas suggested in comments holds true.
- Perform first time setup Lumia 920 - Knowyourmobile
- Nokia Lumia 830 user setup guide - Geeksquas
- Nokia Lumia 625 Setup Wizard - ee.co.uk