gloss ± glossary ± summary ± review ± index

[JohnDenker]

There is a ton of education research devoted to encouraging reasoning in preference to mindless rote regurgitation. Entire books have been written on the subject. At the very least, this suggests a two-part test that can be applied to more-or-less every detail in a textbook:

• Does this invite or require reasoning?
• Does this invite or require mindless rote?

A definition that is incorrect, circular, preposterous, or otherwise incomprehensible flunks this test instantly.

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• A gloss, by definition, serves to define, explain, or translate a difficult word or passage. Glosses are often found in the margin of the text. Originally they were written between the lines of the text. Sometimes HTML uses hover/mouseover/flyouts for this purpose.
• By extension, a collection of explanations is called a glossary. It can serve as a miniature vocabulary or dictionary for a specialized field. For example, a student of Shakespeare might benefit from a glossary of Elizabethan vocabulary words, and Elizabethan dirty jokes.
• A summary is something else entirely.
• An index is something else yet again.

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Let's discuss structure and sequencing. What's optimal for a purely pedagogical work is not optimal for a reference work, and vice versa. It's possible for a given book to serve both purposes, but not simultaneously, so it is important to keep track of which is which. For example, a terse glossary is useful as a reference work, but you wouldn't want to use it as a starting place for learning the subject.

The following make sense to me:

• Glosses -- In the body of the text, line by line, serving to define a difficult word or explain a difficult passage.
• Chapter Summary -- At the end of each chapter, serving as a reminder, serving to emphasize key concepts and principles.
• Index -- Useful when using the book as a reference.
• Legend or Key to the Notation (as in the existing Appendix A) -- Useful as a reference.
• Glossary -- A separate slim volume, serving as a reference book unto itself.
• In contrast, IMHO it makes no sense to have «chapter glossaries» in a textbook.
  • A «chapter glossary» does not serve the reference purpose, because it's too disorganized. I don't want to look through 34 different micro-glossaries trying to find an explanation for this-or-that concept. Also the existing «chapter glossaries» are too unsystematic to be useful as a reference; the coverage of key concepts is spotty at best.
  • A «chapter glossary» does not serve the pedagogical purpose, because it places far too much emphasis on terminology rather than concepts. It leads students into temptation, promoting rote at the expense of reasoning. It defines words in terms of words, rather than explaining the concepts. Small changes do not suffice to fix this problem, because with rare exceptions, physics concepts do not lend themselves to pithy, dictionary-style definitions.
  • If you already have a textbook, any purpose a genuine glossary could possibly serve is better served by an index that points into the body of the text. As an illustration of what I mean, the examples used to explain the term «change» on page 8 are much more informative than the dictionary-style definition in the «chapter glossary» on page 27. It would be incomparably more practical to have an index entry that points to page 8, rather than an unhelpful «chapter glossary» entry.
  • Conversely, a stand-alone glossary only makes sense if you don't have a textbook at hand.
  • When a «chapter glossary» takes the place of the traditional chapter summary, it tells readers that terminology is being emphasized (rather than concepts).

Bottom line: For these reasons among others, the idea of a «chapter glossary» seems like bad strategy. It's not a good glossary, it's not a good summary, and it's not a good index. It suggests a rote terminology-based approach that is the opposite and the enemy of the principles-based or concepts-based approach.

Suggestions:

1. Get rid of the «chapter glossaries».
2. The terms that heretofore appeared in the «chapter glossaries» should be glossed in the body of the text, as needed, where needed.
3. The terms that heretofore appeared in the «chapter glossaries» should appear in the index. The index should point to the places where the terms are introduced, explained, used, et cetera.
4. Second-best idea: Each chapter could perhaps have a _Chapter Summary_ that focuses on concepts (not terminology). As an example of what I mean, the «branch rule» as glossarized on page 841 is not an important principle. It's not worth defining, much less emphasizing. The relevant principle is conservation of charge aka continuity of current. Conservation of charge would be inappropriate for inclusion in the chapter 31 «chapter glossary» ... but it would be highly appropriate for inclusion in the chapter 31 Chapter Summary (among many other places).
5. Better idea: At various places, including at the end of chapters, there should be _Review_ sections that cover everything up to that point. This would put things in perspective. It would emphasize the unity and grandeur of physics.

See #181 for a catalog of index-related issues.

[ericmazur]

My original intent was to combine all the glossaries into one, big glossary -- in part to check consistency throughout the book. Never got around doing that. Will get to it!

[JohnDenker]

Right. Having one big glossary would be useful.

1. Note that it is a common and reasonable practice to integrate the glossary into the index. The index was in need of repairs already.
2. Meanwhile, as an almost-separate issue, it would be nice to have a chapter _summary_ at the end of each chapter. Summary, rather than glossary.

The chapter summary should focus on ideas, not terminology. On page VII the book endorses the pedagogical principle of ideas before names. I would say it slightly differently: ideas are more important than names. Ideas should be primary not just chronologically. They should be first introduced and last reviewed. They should be the foundation and the finial.

A more general discussion of "ideas before name" can be found in item #177.