Romanization of kanji compounds: when are spaces used?

Question

I don't know if the answer depends on the system used. Information on this is welcome too, but mainly I'm interested in the Hepburn system.

When romanizing a kanji compound, how do you decide if you should use a space or not? For example, should 女教師 be "Onnakyoushi" or "Onna Kyoushi"? Should 生徒会長 be "Seitokaichou" or "Seito Kaichou" or perhaps even "Seitokai Chou"? What about 沖縄開発庁長官, 銀河鉄道, 銀魂, 修学旅行?

Is there even a correct\established method, or is it just a matter of preference and there are no right or wrong answers?

Answer 1

Romanization conventions are a bit fuzzy. Generally speaking, the practice I've seen is to group the romaji based on the breakdown of a longer kanji string into singles or two- or three-kanji compounds, based on the underlying semantics. Some folks might use hyphens to clarify three-kanji compounds.

To use your examples, I might romanize like:

• 女教師: 女{おんな} here is clearly an independent lexeme, as indicated also by its reading -- onna is kun'yomi, while kyōshi is on'yomi.
  → onna kyōshi
• 生徒会長: This is 生徒会{せいとかい} + 長{ちょう}, as in the head (長) of the student's (生徒) association (会) → I've seen various renderings of this kind of structure; subjectively, I think the last one is the least user-friendly.
  → seitokai chō, seitokai-chō, or seitokaichō
• 沖縄開発庁長官: This is composed of three lexemes: 沖縄{おきなわ} + 開発庁{かいはつちょう} + 長官{ちょうかん}. The middle one itself is 開発{かいはつ} + 庁{ちょう}, which could be hyphenated.
  → Okinawa Kaihatsu-chō Chōkan, or Okinawa Kaihatsuchō Chōkan
• 銀河鉄道: Two lexemes: 銀河{ぎんが} + 鉄道{てつどう}.
  → Ginga Tetsudō
• 銀魂: This could be parsed either as two lexemes, 銀{ぎん} (on'yomi) + 魂{たま} (kun'yomi), or as a single name, 銀魂{ぎんたま}.
  → Gin Tama, or Gintama
• 修学旅行: Two lexemes, as 修学{しゅうがく} + 旅行{りょこう}.
  → shūgaku ryokō

All that said, if you're looking to romanize the name of an organization or job title (such as the 沖縄開発庁長官), google around a bit -- there might already be an official romanization in use.