Training Morse Code Who, When, Why, and How
What is Morse Code? • Most people are familiar with the general concept of Morse Code • It is a method of communicating that is composed of two “symbols” • Dit – spelled “*” • Dah – Spelled “-” • But just what are these symbols?
What is Morse Code? • Tom King, from the University of Wisconsin – Eau Claire refers to Morse as a “language” • Languages are “words, methods of combining them used and understood by a community. • Morse does not properly fit this definition, since the words used are the same as in the enclosing language
What is Morse Code? • Morse may be thought of as an alphabet • Alphabets are sets signs or symbols used as equivalents for letters • Morse symbols are used to spell letters in order to form words in the English language.
Language Representation • Written languages are a trade-off between the amount of information conveyed in a single symbol and the number of symbols that must be used.
Language Representation • Information theory says that information is derived from the amount of uncertainty in a situation. • When there are many options, there is a great deal of uncertainty in the situation, and each symbol contains more information. • When there are only a few options, each symbol conveys less information, because there is less uncertainty
Language Representation • Using this model, Chinese pictograms contain a great deal of information, because there are so many of them • An educated Mandarin must know around 7000 symbols
Language Representation • European alphabets contain between 20 and 30 symbols • each symbol conveys a moderate amount of information
Language Representation • Morse Code contains only two symbols • Each symbol conveys very little information.
Language Representation • The number of symbols required to convey a concept varies inversely with the information carried by each symbol • In Mandarin, many concepts can be expressed in a single symbol, resulting in a compact language • In English, the average word length is around 5 symbols • In Morse, the average word is around 15 symbols long
Language Representation • The number of symbols must be balanced against the difficulty of creating a single symbol • In Mandarin, symbols are sometimes very complex, and changes in strokes can change the meaning
Language Representation • In English, each symbol is easier to make, but more must be used
Language Representation • In Morse, each symbol is very easy to use, but more must be used to convey information. • Originally, the Morse symbols were designed for easy transmission with primitive communications technology • For computers, it is the easy of creating symbols that makes Morse a desirable method of generating text.
Language Representation • In addition to being the Morse alphabet being easy to produce, the Words of the Morse language (letters in English) have spellings that are based on how frequently they are used.
Language Representation • When Morse originally created his code, he recognized that some letters (e & t for example) are used much more often that others (Q and Z for example)
Language Representation • He assigned the shortest codes to the most frequently used letters, so that overall productivity goes up.
Language Representation • For example, Dickens’ “American Notes” contains 352,406 letters • In un-optimized code, this would result in 1,111,434 symbols to generate in Morse • In actual Morse, the novel could be written with 893,266 symbols, for a savings of about 20%!
Language Representation • Several features of Morse would make this task even easier that it seems: • For two-switch Morse, multiple symbols (a row of dits or dahs) can be generated with a single switch activation
Who Should Use Morse? • Within the access hierarchy, anyone who can access a physical keyboard with fluency will find it faster or easier than Morse • This includes • Expanded Keyboards • Standard keyboards • Minikeyboards
Who Should Use Morse? • With modern technology, in an environment that supports it, speech input will generally be faster, but not easier than Morse • The client must have consistent speech and good breath support • The client must have good cognition (better than that required for Morse) • The client be in an environment where constant talking will not distract others
Who Should Use Morse? • A person who has difficulty with new learning may find Morse difficult to remember, and should use an input method with fewer cognitive demands • On-screen keyboards draw on old learning, when available • On-screen keyboards show all options at once, so may be easier for many people than Morse
Who Should Use Morse? • The person with only a single motor site, and without the ability to performed times movements will not be able to use Morse
Who Should Use Morse? • So, who is left? • Clients with limited ROM and/or limited fine motor control • Clients with ability to learn new concepts • Clients with “good” thinking skills • Able to read at 3rd grade level • Note: This may be a conservative standard!
Who Should Use Morse? • Conventional thinking about Morse Code considers it only for language applications • Morse can also be used in leisure and EADL applications • Even the client who cannot learn Morse with the fluency to write can learn enough Morse for some leisure and environmental control applications. • This is a valid application, even if some other tool must be used for writing!
Why use Morse? • It’s fast! • Typical users using sip & puff switches may reach typing speeds of 20 to 25 words per minute • Compare this with typical on-screen keyboard speeds of 15 to 20 wpm!
Why use Morse? • It is transparent • Nearly all input methods for people with disabilities require a degree of attention • This can be termed “cognitive overhead” • It is mental power that is not available to the task at hand. • Proficient users of Morse Code say that “they” do not know the code. They just think words, and they appear on the screen. • This is similar to the process of touch typing, where your fingers know the keys.
Why use Morse? • Morse code can be come completely automatic • This means that there is virtually no cognitive overhead once it is learned.
Isn’t Morse Hard to Learn? • Learning Morse Code is like learning to touch type, as opposed to “hunt and peck” techniques like on-screen keyboards • There is a certain amount of work that goes into learning to touch type • When you first start learning, it seems very difficult, and slower than hunt-and-peck typing • You have to learn a lot before you even start!
Isn’t Morse Hard to Learn? • Once you have learned to touch type, almost no-one goes back to hunt-and-peck typing • This is because it is actually easier (once learned) • It is faster • It is more efficient
Isn’t Morse Hard to Learn? • Like Touch Typing, learning Morse Code is an investment in the client’s future. • Once the time and energy is invested, it will be paid back many times over, for the rest of the client’s life!
How hard is Morse? • Many clinicians in school system practice will say that they would not consider teaching Morse to a young child because it is too difficult. • They would allow the child to use a less efficient method until fourth or fifth grade, then consider changing to Morse
How hard is Morse? • In the first four or five years, the child has learned to become frustrated at the difficulty of writing!
How hard is Morse? • But, consider: • Developmentally, children first learn to “scribble” • Next they learn to produce horizontal lines • Next, they learn to scribble vertical lines • Next they learn crosses • Finally, they learn diagonals.
How hard is Morse? • Now, consider the process in teaching a child to generate the character “A” • First, the child must make a diagonal stroke • Next, the child must make a matching diagonal stroke, touching at the top! • Finally, the child must make a horizontal stroke, starting at one diagonal, ending at the other.
How hard is Morse? • Compare this to the process for making an “A” using Morse code, with two switches • First, the child presses and releases one switch • Next the child presses and releases the second switch
How hard is Morse? • Yet, we feel that the first is a reasonable activity for the child in kindergarten, and the second is too hard!
How hard is Morse? • There are, of course, some differences: • In written language, the movement pattern “looks” like the letter to be produced. • This supports eye-hand coordination • In Morse, the movement pattern doesn’t resemble the desired outcome. • This is similar to the issues of keyboarding, where the movement patterns are not like the letters produced. • But, again, we start children keyboarding in the first grade, and think Morse is too hard!
How hard is Morse? • I suggest that Morse should be started, for the child with significant disabilities, at the same age that typically developing children are learning to make letters with a pencil! • This avoids learned helplessness • It also allows the child the maximum opportunities to participate in the curriculum.
Morse and Timing • The standard Morse definition for single switch Morse code is that: • A dit is the basic unit of measure, and each sender may have a different dit length • A “dah” is three dits long. That is, to produce a “dah”, the switch must be held down three times as long as for a dit. • The space between parts of a letter is one dit • The space between letters is 1 dah • The space between words is 7 dits
Morse and Timing • Note that this is for radio Morse, which doesn’t have characters for spaces • In computer Morse, the space for end of letter is five dits (generally), and words are separated by space characters
Morse and Timing • For two switch Morse, dits and dahs can be the same length of switch closure, since there is no ambiguity about which switch was pressed. • But, for both one and two switch Morse, the sender must be able to produce switch closures at a repeatable rate.
Morse and Timing • If the client cannot produce switch closures with repeatable timing, then one and two-switch Morse are not options • For this client, you can use three switch Morse, which removes the need for timing!
Morse and Sound • Virtually all Morse code products for computer access generate tones when a switch is closed.
Morse and Sound • This tone, called a “side tone,” is vital to the learning of Morse
Morse and Sound • In some settings, where the noise may be a distraction, some might be tempted to turn it off. • Don’t do it! • If the environment won’t tolerate the sound of the side-tone, provide the user with earphones so that the sound doesn’t distract others, but is available to the sender. • The sound is essential because the user learns code as sound patterns, or tunes. • Without the tunes, code is much harder to learn.
Computer Morse Vs. Radio Morse • In 1980, Al Ross, at the University of Washington created a communication system using Morse Code • This code was later included in the Adaptive Firmware Card, for the Apple II computer
Computer Morse Vs. Radio Morse • When code was being used for communication via electronic devices, some additions were necessary • Standard Morse includes the letters, numbers, period, end of work, and end of message codes • For computers, you need some additional codes, for punctuation, shift keys, and such
Computer Morse Vs. Radio Morse • To add then necessary codes, Al used the unassigned codes, and arbitrarily gave them meanings • There was no effort to optimize these codes, because the relative frequency of “%” versus “&” is generally unimportant
Computer Morse Vs. Radio Morse • Each subsequent developer of a Morse product used the same technique (random assignment) to extend standard Morse • As a result, each Morse product has slightly different codes for the extension characters
Computer Morse Vs. Radio Morse • To help manage this chaos, Morse 2000 Outreach published a “standard computer Morse” definition in the hopes that future developers would use the standard, and order could be imposed