Explain how standardization lets products and data from different makers work together.
Sort standards by who set them and how, and tell a de facto standard from a de jure standard.
Distinguish a forum standard from the other two by the fact that its specification comes from a body formed by companies and similar organizations.
Explain that a JAN code is a numbering rule printed on products as a barcode, and that a QR code is a two-dimensional code with dots laid out both vertically and horizontally.
A de facto standard (デファクトスタンダード) is a product or specification from one company or group that came to be treated as the standard in practice because so many people in the market used it.
It needs no review or approval by a public body: once users and other companies line up behind the specification, it does the job of a standard. PC operating systems and keyboard layouts are examples of specifications that won out in competition. Some are later adopted again as official standards after they have spread.
AnalogyNobody assigned the seats, yet after everyone keeps sitting in the same spot, that becomes the class seating plan.
How to rememberDe facto is Latin for "in fact": not what the rules say, but how things actually are.
Exam points
ExamA de facto standard (デファクトスタンダード) is a specification made by a particular company or similar party that came to be treated as the industry standard after it was widely adopted.
A de jure standard (デジュレスタンダード) is an official standard that a standards body has reviewed and formally adopted following set procedures.
Standardization means bringing things such as product specifications and data formats into line with a shared set of rules. International or national bodies whose job is to write those rules are called standards bodies, and ISO (the International Organization for Standardization) is the best-known one worldwide. A fixed procedure runs from drafting through gathering stakeholder comments to approval, and only what passes through it becomes a standard.
AnalogyNot a popularity vote, but like a parliament debating and voting by a fixed procedure: the way the decision is made is itself formally laid down.
How to rememberDe jure is Latin for "by law". Jure belongs to the same "law" family as the English words jury and justice.
Exam points
ExamWhen data formats and the like are standardized (標準化), devices and products from different makers can handle the data directly, with no need to worry about which company made the other side.
A forum standard (フォーラム標準) is a specification set by a body (a forum) that several companies and others in a technical field form together.
How standards arise (main types)
De facto standard: from market adoption
Forum standard: made by a body that companies formed
De jure standard: adopted by an official standards body
Compared with the procedures of official standards bodies, this route makes it easier to produce specifications quickly as technology changes. Bluetooth for wireless communication is one example, with its specification managed by an industry group.
AnalogyLike the shops on a local high street forming an association that sets the rules for a gift voucher every member shop accepts.
How to rememberA forum was the square where people gathered in ancient Rome. Picture "the standard written by the meeting place companies built together" and it comes back easily.
Exam points
ExamA forum standard (フォーラム標準) is one where interested companies and others set up their own body to write the specification, and it spreads as member companies release products that follow it.
A barcode (バーコード) is an identification mark that encodes numbers and other characters as a row of bars and spaces of varying width, read by a scanner that shines light on it.
Printed as bars and spaces
Scanner reads it with light
Bar pattern turned back into a number
System uses the number
A system such as the checkout uses the number to record which item was sold.
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Because the bars run in only one horizontal direction, a barcode holds no more than a few dozen digits or letters. It is faster than typing by hand and less prone to keying errors, so it is used widely in logistics and in POS (point-of-sale) systems that record each item at the checkout as it is sold.
AnalogyIt is like Morse code, which spells letters with long and short sounds, redrawn on paper as thick and thin lines.
How to rememberA bar is a stick or rod in English, so a barcode is literally a code made of rods in a row.
Exam points
ExamBarcode (バーコード) is the name of the method that represents a number as bars and spaces, and the JAN code (JANコード), Japan's common product numbering rule, is printed on goods using this method.
A JAN code (JANコード) is Japan's common product code, which gives each kind of product (item) a unique number so it can be told apart, and it is printed on goods as a barcode.
Part (from the start)
How it is set
What it tells you
Manufacturer code (now called the GS1 Company Prefix by GS1 Japan; includes the country number)
Assigned on application to the managing organization
Which company the product is from
Item code
Set by the company for each of its products
Which of that company's products it is
Check digit
Calculated from the other digits
Catches misreads and keying errors
There are two lengths: a 13-digit standard type and an 8-digit short type. The last digit, the check digit, is calculated from the other digits by a fixed formula and is used to detect errors in the number that was read. Details such as the product name are not stored in the number itself; the store's system looks them up from registered data using the number.
AnalogyThink of menu numbers in a food court: the operator hands out stall numbers so none overlap, and each stall numbers its own dishes. The same dish keeps the same number however many plates of it are served.
How to rememberJAN stands for Japanese Article Number, and an article here means an item of goods.
Exam points
ExamA JAN code (JANコード) runs, from the start, the manufacturer code (メーカコード) for the company, the item code (商品アイテムコード) for that company's product, and the check digit (チェックディジット) for verification. What the number tells you is which company and which of its items.
ExamThe company part is assigned by the managing organization so that it never overlaps with another company, while each company sets the product part itself. One scheme can therefore handle goods from many companies without mixing them up.
ExamSorted by what they identify, ISBN is the number that pins down a book worldwide, while the JAN code (JANコード) tells apart general goods sold in stores.
A QR code (QRコード) is a two-dimensional code (二次元コード) that represents data with black and white dots laid out both vertically and horizontally inside a square.
Because the data covers the whole area, it can hold thousands of digits and handle letters and kanji as well. Even if part of it is dirty or missing, an error-correction mechanism can restore the original data.
AnalogyCompared with a memo box that has a single line, squared manuscript paper of the same size holds far more characters.
How to rememberQR stands for Quick Response, so the name itself says it is meant to be read quickly.
Exam points
ExamA QR code (QRコード) holds data as a pattern in two directions, so one code can carry far more data than a JAN code (JANコード).
ExamA QR code (QRコード) uses the square markers in three of its corners (position detection patterns, 位置検出パターン) to work out its orientation, so it can be read whichever way it faces the scanner.