Ken Schwaber provides some background to the PSM and PSD certifications
In 2010 Ken Schwaber was interviewed by InfoQ about why he had set up Scrum.org. The complete interview is here: http://www.infoq.com/news/2010/08/kenschwaber-interview-part1. There were a couple of questions that specifically related to certification and are worth highlighting...
INFOQ: Tell us about the Scrum.Org credentialing process. For example, how does a person become certified as a Professional Scrum Master at Scrum.Org?
KEN: Credentialing, or assessment, begins with a widely accepted body of knowledge. With Scrum, that is the Scrum Guide, the definition of Scrum by Jeff Sutherland and myself, the creators of Scrum. The assessment is a set of questions that tests whether a person knows that body of knowledge. We currently certify a person if they demonstrate a knowledge level of 85% or higher.
We also have assessments of a person’s knowledge of using Scrum to build software products. This is the PSM II assessment. The third assessment is whether a person has an adequate degree of knowledge of how to build an increment of software in a Scrum team using a specific technology stack (.NET and JAVA, currently). Scrum.org partners with organizations that develop training programs to help people acquire this knowledge, but training is completely separate from assessment.
People can be knowledgeable without being trained.
INFOQ: Ken, tell us about the Professional Scrum Developer credential.
KEN: Martin Fowler said that many implementations of Scrum were “flaccid” last year. By this he meant that the developers on the Scrum teams were unable to build a solid increment at the end of every Sprint. The iteration would either be poor quality or it wouldn’t be truly complete. Upon talking with Martin, he and I concurred that what we had observed were developers that were not familiar with time-boxed work using modern engineering practices (like acceptance test driven development and refactoring) or how to develop them in modern engineering development environments, such as with source control, continuous build, and frequent automated integration and integration testing.
Scrum reduces an entire development cycle down to one Sprint, and leaves the process for turning a requirements into something potentially shippable up to the developers on the Scrum Team. That is a seismic shift for many developers, because it exposes all of the inefficiencies and waste that pervaded the waterfall cycle.
Extreme Programming made an important step toward creating a process that addressed that problem. However, XP and XP training is not mainstream. So I went to the product companies, those that tool the engineering development environment. We partnered to show their customers how to build a solid increment every Sprint. The program is called the Professional Scrum Developer program, with a suffix indicating the tool and technology stack (.NET, Java).
I created an assessment for the Professional Scrum Developer program for the same reason that I did for the Scrum Master skill set. I wanted people to be able to assess their knowledge of how to be a developer in a Scrum Team and environment. The assessment derives from the course material which derives from industry best practices, tools specific usage, and Scrum. I intended this assessment to be a self-evaluation activity. We also certify anyone who demonstates an adequate knowledge a Professional Scrum Master certification. Much to my surprise, a number of organizations are working with us to use the assessment as a way of screening those qualified to be part of the Team (of developers) in a Scrum project. This is particularly useful in relationship to qualifying and engaging contractors.
Link to interview has an extra period ('.') at the end resulting in a 404.
Should be http://www.infoq.com/news/2010/08/kenschwaber-interview-part1