That's a positivist perspective on research and knowledge. While your perspective on validity might be fitting for quantitative research, for an exploratory expose and kinds of qualitative research some look for other measures of validity and quality. There is an enormous amount of research (papers) on this topic, just look for "qualitative research validity". As it is more a matter of perspective, there often seem some incommensurability creeping into these discussions.
In this case, I believe that a professional/experienced educator who has tried teaching introductory programming can, given their own experiences, relate, understand, and build on the concepts in the article to improve their own teaching and understanding of teaching/learning introductory programming. This is sometimes called communicative generalization (see Smaling: http://www.ualberta.ca/~iiqm/backissues/2_1/html/smaling.htm... ).
For example, to me, as a computer science teacher in high school, I recognize a lot of the issues discussed in the article. Reading the article I am able to link these issues and solutions to my experiences in class and decide to what extent it is credible and trustworthy. Furthermore, and more importantly, I can more easily apply results this kind of research in my daily practice than I can results of (rigorous) quantitative research as that almost always is taken out of context and ' clinically' due to fixing variables that aren't fixed in real life situations (i.e. the classroom, the students (holistic), environment).
I'm well aware of qualitative research, but he doesn't even have that. And, while I agree that you can translate and interpret the major themes, all you have done at that point is recognize that you have a similar problem and have formed a hypothesis that needs to be tested. You cannot assume that your method of fixing the identified problem will actually work until it is tested.
True. On the other hand, it allows the professional/expert to have a good idea if it might work. And, if so, if it is worth testing out or not. In my opinion the value of this kind of research and/or informed opinion pieces is local in scope and should be treated as such. Don't base your educational policy on this kind of research, for that you'd better look for quantitative and, preferably, longitudinal studies.
In this case, I believe that a professional/experienced educator who has tried teaching introductory programming can, given their own experiences, relate, understand, and build on the concepts in the article to improve their own teaching and understanding of teaching/learning introductory programming. This is sometimes called communicative generalization (see Smaling: http://www.ualberta.ca/~iiqm/backissues/2_1/html/smaling.htm... ).
For example, to me, as a computer science teacher in high school, I recognize a lot of the issues discussed in the article. Reading the article I am able to link these issues and solutions to my experiences in class and decide to what extent it is credible and trustworthy. Furthermore, and more importantly, I can more easily apply results this kind of research in my daily practice than I can results of (rigorous) quantitative research as that almost always is taken out of context and ' clinically' due to fixing variables that aren't fixed in real life situations (i.e. the classroom, the students (holistic), environment).