Debate on mixed script and hangeul exclusivity

The foremost problem at the centre of this debate is the use of Hanja. Mixed script was a commonly used means of writing, although Hangŭl exclusive writing has been used concurrently, in Korea after the decline of literary Chinese, known as hanmun (Korean: 한문; Hanja: 漢文). Mixed script could be commonly found in non-fiction writing, news papers, etc. until the enacting of Park Chung Hee's 5 Year Plan for Hangŭl Exclusivity[1] hangŭl jŏnyong ogaenyŏn gyehuik an (Korean: 한글전용 5개년 계획안; Hanja: 한글專用 5個年 計劃案) in 1968 banned the use and teaching of Hanja in public schools, as well as forbade its use in the military, with the goal of eliminating Hanja in writing by 1972 through legislative and executive means. However, due to public backlash, in 1972 Park's government allowed for the teaching of Hanja in special classes but maintained a ban on Hanja use in textbooks and other learning materials outside of the classes. This reverse step however, was optional so the availability of Hanja education was dependent on the school one went to. Park's Hanja ban was not formally lifted until 1992 under the government of Kim Young-Sam. In 1999 the government of Kim Dae-Jung actively promoted Hanja by placing it on signs on the road, at bus stops, and in subways. In 1999 Han Mun was reintroduced as a school elective and in 2001 the Hanja Proficiency Test hanja nŭngryŏk gŏmjŏng sihŏm (Korean: 한자능력검정시험; Hanja: 漢字能力檢定試驗) was introduced. In 2005 an older law, the Law Concerning Hangul Exclusivity hangŭl jŏnyonge gwahak pŏmnyul (Korean: 한글전용에 관한 법률; Hanja: 한글專用에 關한 法律) was repealed as well. In 2013 all elementary schools in Seoul started teaching Hanja. However, the result is that Koreans who were educated in this period having never been formally educated in Hanja are unable to use them and thus the use of Hanja has plummeted in orthography until the modern day. Where Hanja is now very rarely used and is almost only used for abbreviations in newspaper headlines (e.g. 中 for China, 韓 for Korea, 美 for the United States, 日 for Japan, etc.), for clarification in text where a word might be confused for another due to homophones (e.g. 이사장(李 社長) vs. 이사장(理事長)), or for stylistic use such as the 辛 (Korean: 신라면; Hanja: 辛拉麵) used on Shin Ramyŏn packaging.

Proponents of the use of mixed script of cite information theory as an argument against Hangŭl exclusivity, with the premise being that Hangŭl has a much lower amount of information in comparison to Hanja. Hangŭl has 24 letters: 14 consonants; ㄱ ㄲ ㄴ ㄷ ㄸ ㄹ ㅁ ㅂ ㅃ ㅅ ㅆ ㅇ ㅈ ㅉ ㅊ ㅋ ㅌ ㅍ ㅎ, and 10 vowels;ㅏ ㅐ ㅑ ㅒ ㅓ ㅔ ㅕ ㅖ ㅗ ㅘ ㅙ ㅚ ㅛ ㅜ ㅝ ㅞ ㅟ ㅠ ㅡ ㅢ ㅣ. Whereas Hanja are logograms consisting of over 80,000 characters, around 2,000 of which are considered "common use" in Korea.[2] Thus, if one assumes Hangŭl occurs with equal probability and is independent (which is not true as the actual probability for Hangul ranges from 0.122 for ㅇ and 0.002 for ㅋ), each Hangŭl letter occurs 1/24 of the time whilst each Hanja occurs 1/2,000 of the time. Thus, the entropy of Hangul is only 4.75 bits-per-symbol, while the entropy of Hanja is 10.96 bits-per-symbol (and 15.29 bits-per-symbol, when 40,000 symbols are considered). This means that each character of Hanja conveys much more information than each letter of Hangŭl. This data is of course not entirely correct, and in actuality certain symbols do occur with more frequency than others, and therefore the entropy will be much lower. However, this does not detract from the finding that each character of Hanja conveys more information than each letter of Hangul as there are still many more Hanja characters than Hangul letters. The fact that Hanja conveys more information than Hangul has ramifications in the semantic meaning of each character. Using the word "일" as an example, composed of the Hangŭl letters ㅇ, ㅣ, and ㄹ. In only three letters, there is much ambiguity over the meaning of the Hangul block, as it could mean 一(일) one, 日(일) day, or even a native Korean word for work (일). As shown, writing the Hanja makes it clear and obvious which "일" the writer means. To take the example further, compare Hanja to their Hangŭl pronunciation and corresponding native word, or eumhun (Korean: 음훈; Hanja: 音訓). See below:

• 車 (1 character) → Hanja: 차 (2 letters) car
• 天 (1 character) → Hanja: 천 (3 letters), Native: 하늘 (5 letters) sky
• 止 (1 character) → Hanja: 지 (2 letters), Native: 멈추다 (7 letters) to stop
• 褰 (1 character) → Hanja: 건 (3 letters), Native: 옷을걷어올리다 (18 letters) to hang up clothes
• 蔭 (1 character) → Hanja: 음 (3 letters), Native: 조상의 공덕에 의하여 맡은 벼슬 (33 letters) A bureaucratic position attained based on merits of an ancestor

Many times Hangŭl may appear more compact simply due to its nature of being stacked into syllable blocks. However, based on actual brevity and the amount of information conveyed from an information theory perspective, Hanja conveys meaning and information much faster and more efficiently than Hangŭl. A mixed-script orthography with an optimal distribution of probability between Hanja and Hangŭl would increase the information content of writing. This in turn shortens the amount of symbols needed to convey the same meaning while maintaining ease of learning.

This is done by Hanja allowing one to easily coin words and expressions that would otherwise be quite long and complex in Native Korean. For example, the Sino-Korean phrase of "No smoking allowed" is 금연/禁煙, while the Pure-Korean equivalent is 담배 피우지 마. One common argument presented by Hangul Exclusivity proponents is to study the individual meaning of each morpheme without learning the actual Hanja characters themselves. However, the sheer number of homonyms present in Sino-Korean morphemes, which the Hanja characters themselves properly separate, reduces the practicality of this approach. For example, when comparing the words 전부/全部 and 전쟁/戰爭, which mean entirety and war respectively, the 전 in both words have completely different meanings and Hanja characters. On the other hand, Latin roots in the English language have very few homonyms. For example, words that have pyro- as a root will almost always mean fire, but the Sino-Korean root for fire, 화/火, is spelled identically in Hangul with many other roots such as 化, 和, 貨, 話, 華, 花, 畵, 禾, 禍, and 靴. As a result, there are many words as a whole that are spelled identically in Hangul, but vary widely in meaning. 수도 for instance has 12 different meanings, depending on the Hanja characters, such as 首都 (capital city), 手刀 (hand knife), 水都 (water city, such as Venice or Suzhou), or 修道, spiritual discipline. In addition, the number of homonyms causes severe limitations to vocabulary acquisition when homophonous words are being transcribed entirely phonetically, and purely phonetic transcription reduces understanding and depth of knowledge of Sino-Korean words. As a result, text can still be shorter and easier to comprehend in Mixed-Script Korean than in Hangul-only Korean, even though 1 Hanja character corresponds to 1 Hangul block.