Katakana Analysis Final

Most of the Katakana my group and I found were loan words on Japanese products.  I think more onomatopoeia would be found in anime.  

Here are two katakana I found:

1. Loanword, コンピューター, computer, Daily Sun Japanese newspaper
This might be written in katakana because scientific and technical terms are often written in katakana.  Also, I realize wikipedia isn't always the best source, but it says, "Katakana were used for telegrams in Japan before 1988, and for computer systems—before the introduction of multibyte characters—in the 1980s. Most computers in that era used katakana instead of kanji or hiragana for output." 

2. Loanword, コーラ, Cola, Coca Cola-flavored hard candy
The purpose of writing this in katakana might be because Cola is a foreign invention, a foreign word, and a name. Katakana is often used for transcribing words from foreign languages.

Some words are transcribed into katakana because it does not make sense to change a foreign name.  It would not have a kanji alternative if the Chinese were not introduced to the foreign word.  The katakana show that the word is foreign or unusual, which helps readers know that they aren't looking at traditional Japanese word.

Each textbook is different in explaining katakana because there are exceptions to why certain words are in katakana.  Some names are in katakana; some are not.  "Computer" could have been written in hiragana or kanji (it's not a loanword, name, or onomatopoeia), but somehow it's in katakana.  Textbooks don't give strict rules for what words are in katakana because there are none.  In general, most katakana are foreign or unusual sounding words, onomatopoeia, words for emphasis, or names.

According to Let's Learn Katakana, by Yasuko Kosaka Mitamura, some katakana has replaced disused or complicated kanji.   Mitamura also adds that katakana was used for all computer work until the 1980's, most likely for its legibility and simplicity.  Furniture, companies, animals and plants, and colloquial expressions are sometimes in katakana.  I have deduced that there are many different reasons for writing certain words in Katakana.