I've found that phrase "Educational pearl" on this page and have no idea what it means. Can someone explain it for me please?
It is a "pearl of wisdom," or some sort of good, concise advice, which you could apply to education. In this case, they are talking about an effective method for teaching computer science.
I had thought that it might be intended to have a double meaning with the Perl programming language, but they don't mention this language in the article.
I just found this question on Google and it looks like none of the answers here tell the full story.
This use of the word "Pearl" here is a take on a type of paper in the Functional Programming community called a "Functional Pearl", a concept that was began in the Journal of Functional Programming and which was based on the original "Programming Pearls" series in the Communications of the ACM published . In that original series the word Pearl was chosen to reflect that these "Pearls" were solutions that had been polished over time into particularly elegant programming solutions (as Joe McMahon conjectured). The programming pearls series was also published as a book.
As described here and also on the ICFP website, a Functional Pearl should be elegant, fun and instructive.
This meme is used sometimes used with a twist (mostly in the Programming Language community). Here they have an "Educational Pearl", I've also seen a "Declarative Pearl" and a "Scheme Pearl". They are meant to imply the same style as a Functional Pearl but in a different or more specific domain than Functional Programming.
It seems that the word pearl, in this context, refers to an official term, i.e. pearl. The title and abstract hint that this "Educational Pearl" is one of many. Perhaps "Educational Pearl" is merely the title of a series of which this publication is a part. (cf. scheme2006, list of publications)
It is possible that there is some meaning intended for the use of "pearl" to describe these documents, but it seems that the meaning would be hidden from the casual browser of any one of these publications. Perhaps it has some meaning to the faculty and students at this institution.
Oxford English Dictionary, s.v. "Pearl", 2.b.:
A precious or valuable thing; a virtuous or highly esteemed person; a fine example or type; a pertinent or wise saying (freq. in pearl of wisdom).
It's interesting to note the implications here: it's a pearl, rather than a gem - this has all the implications of pearl formation: a beautiful thing coming from a small, irritating seed, which has had to grow over time to become precious and valuable. Whether these are actually part of the etymology of the phrase is unknown to me, but I find this interesting to consider.