The four parts of the program are:
That gives us:Now it is time to evaluate how well this program does.
For a word of length , there willbe deletions, -1 transpositions, 26alterations, and 26(+1) insertions, for a total of54+25 (of which a few are typically duplicates).
From that I extracted twotest sets of corrections.
For example,However, if we restrict ourselves to words that are —that is, in the dictionary— then the set is much smaller:We'll also consider corrections that require simple edits.
Our program enumerates all corrections withinedit distance 2.
A small number of progressive leaders of major urban school systems are using school closure and replacement to transform their long-broken districts: Under Chancellor Joel Klein, New York City has closed nearly 100 traditional public schools and opened more than 300 new schools. In 2004, Chicago announced the Renaissance 2010 project, which is built around closing chronically failing schools and opening 100 new public schools by the end of the decade.
So far, only looks at one word at a time.
These principles can be translated easily into urban public education via tools already at our fingertips thanks to chartering: start-ups, replications, and expansions. Chartering has enabled new school starts for nearly 20 years and school replications and expansions for a decade. Chartering has demonstrated clearly that the ingredients of healthy, orderly churn can be brought to bear on public education.
But we'll leave that for another day...
The churn caused by closures isn’t something to be feared; on the contrary, it’s a familiar prerequisite for industry health. Richard Foster and Sarah Kaplan’s brilliant 2001 book Creative Destruction catalogued the ubiquity of turnover in thriving industries, including the eventual loss of once-dominant players. Churn generates new ideas, ensures responsiveness, facilitates needed change, and empowers the best to do more.