Mnemonic learning

A mnemonic (pronounced in American English,  in British English) is a memory aid. Mnemonics are often verbal, something such as a very short poem or a special word used to help a person remember something. They are often used to remember lists. Mnemonics rely not only on repetition to remember facts, but also on associations between easy-to-remember constructs and lists of data, based on the principle that the human mind much more easily remembers data attached to spatial, personal or otherwise meaningful information than that occurring in meaningless sequences. The sequences must make sense though. If a random mnemonic is made up, it is not necessarily a memory aid.

The word mnemonic shares etymology with Mnemosyne, the name of the titan who personified Memory in Greek mythology. The first known reference to mnemonics is the method of loci described in Cicero's De Oratore.

The major assumption is that there are two sorts of memory: the "natural" memory and the "artificial" memory. The former is inborn, and is the one that everyone uses every day. The artificial memory is one that is trained through learning and practicing a variety of mnemonic techniques. The latter can be used to perform feats of memory that are quite extraordinary, impossible to carry out using the natural memory alone.

Techniques
A mnemonic technique is one of many memory aids that is used to create associations among facts that make it easier to remember these facts. Rhyming in poetry has been used since ancient times as a memory aid. For recalling items in a fixed sequence peg lists are especially useful. This method can be applied to unordered lists of things, as well, and can be used to ensure that no item is left out. The method of loci is similar in that ordered lists are the target, but it relies on placing vivid emotive images onto images of places which one has previously visited repeatedly in a particular order. The major system, or phonetic number system can be used to replace the memory of numbers with the memory of sequences of words or images.

Other methods for remembering arbitrary numbers or number sequences use numerological (lit. number+word) systems such as the abjad, where each numeral is represented by a consonant sound.

All of these can be used with the method of substitute words, which replaces an abstract or not easily visualized word or concept with one that is associated with an emotive or striking word. For example, in memorizing the periodic table, boron (which has no image associated with it that one can recall) might be associated with the substitute word "bore." Everyone has a friend who is a bore, and he would be visualized in this connection. Silicon becomes "silly con," and so on.

These techniques appear to make use of the power of the visual cortex to somehow make the memories more readily fixed in one's mind, and last longer than ordinary memories. For example, a number can be remembered as a picture. This makes it easier to retrieve it from memory. Mnemonic techniques should be used in conjunction with active recall to actually be beneficial. For example, it is not enough to look at a mind map; one needs to actively reconstruct it in one's memory. These systems take advantage of the memory's ability to store more information by organizing it into "chunks". Concentration and repetition are still required, though not as much.

Number rhyme system
This is an example of a "peg list". It is useful for remembering ordered lists, especially for people with strong auditory learning styles. The following numbered list is static. Note the rhyme of the digit and the word (one/bun, two/glue, and so on). The items you wish to remember should be associated with each word. A similar system utilizing a combination of this and the preceding "abjad" system can easily yield numbers through 100 or higher.


 * 1) Bun
 * 2) Glue
 * 3) Tea
 * 4) Door
 * 5) Hive
 * 6) Bricks
 * 7) Heaven
 * 8) Slate
 * 9) Line
 * 10) Pen
 * 11) Devon
 * 12) Delve
 * 13) Obscene
 * 14) Cuisine
 * 15) Serene

and so on.

Egg and spear or number shape system
This is another peg system, much like the number-rhyme system but more suitable for those with visual learning styles (a one looks like a candle; a two looks like a swan, and so on).


 * 1) Candle, spear
 * 2) Swan
 * 3) Bosom
 * 4) Sail
 * 5) Hook
 * 6) Club
 * 7) Cliff
 * 8) Hourglass
 * 9) Flag
 * 10) A Candle next to an Egg

Visual mnemonics
Visual mnemonics are very popular in medicine as well as other fields. In this technique, an image portrays characters or objects whose name sounds like the item that has to be memorized. This object then interacts with other similarly portrayed objects that in turn represent associated information.

Examples of simple first letter mnemonics
One common mnemonic device for remembering lists consists of an easily remembered word, phrase, or rhyme whose first letters or are associated with the list items. The idea lends itself well to memorizing hard-to-break passwords as well.

Astronomy

 * Stellar classification uses a peculiar group of letters, easily remembered using the phrase, "Oh Be A Fine Girl, Kiss Me." With two new categories L and T for brown dwarfs, the revised version to "Oh Be A Fine Girl/Guy, Kiss My Lips Tenderly." (Sometimes "Right Now Smack Wow." was added at the end, although these classes are not part of the sequence and are no longer current.)
 * For naming the planets in order from the Sun, the phrases:
 * "My Very Eager Mother Just Sewed Us New Pajamas"
 * "Most Valuable Earth Must Jump Straight Up North Pole"
 * "My Very Educated Mother Just Showed Us Nine Planets"
 * "My Very Easy Method Just Speeds Up Naming Planets"
 * "My Very, Eccentric Mother Just Showed Us Nine Planets"

Biology, medicine, and anatomy
Medical mnemonics are quite common, see. Some of them are less politically correct than others, and some are profane (presumably because their shock value makes them easier to remember). The list below doesn't censor, but in some cases does provide "clean" alternatives.

An example of a visual mnemonic for the drug "hydralazine" could be represented as "lazy hydra" that is on strike holding a sign "NO more work". "NO" in the above case symbolizes Nitrous oxide, which is related to the drug's mechanism of action. For examples of this technique, see.

Computer Science
Mnemonics in computer science tend to be less pervasive as most abbreviations are brief. Some terms still warrant a mnemonic such as People Can't Memorize Computer Industry Acronyms (PCMCIA).

(This is occasionally and ironically rendered "people can't remember computer industry acronyms".)

Cranial nerves

 * (The letters stand for Olfactory nerve, Optic nerve, Occulomotor nerve, Trochlear nerve, Trigeminal nerve, Abducent nerve, Facial nerve, Auditory nerve, Glossopharyngeal nerve, Vagus nerve, Accessory nerve, and Hypoglossal nerve.)

In the ones marked with a "@", the accessory nerve is referred to by its alternate name "Spinal accessory nerve". In the ones marked with "#" the Auditory nerve is referred to by its alternate nane "Vestibulocochlear nerve".

Another to help remember the types of information these nerves carry (sensory, motor, or both) is thus: Some Say Marry Money, But My Brother Says Big Brains Matter More. On Old Olympus' Tiny Tops A Friendly Viking Grew Vines and Hops
 * "Ooh, Ooh, Ooh To Touch And Feel Very Good Velvet. Such Heaven!" @
 * "On Old Olympus' Towering Top A Finn And German Viewed Some Hops" @
 * "On Old Olympus' Tiny Top A Finn And German Viewed Some Hops", or "On Old Olympus' Towering Top A Finely Vested German Viewed A Hawk" (with variations; some say "terraced tops", "towering top(s)" or "topmost top", and "viewed some hops" is sometimes rendered as "vaulted a hedge").
 * "O! O! O! To Touch And Feel A Girl's Vagina And Hymen."
 * "O! O! O! To Touch And Feel Virgin Girls' Vaginas And Hymens." #

External carotid artery branches

 * ''(The letters stand for superior thyroid artery, ascending pharyngeal artery, lingual artery, facial artery, occipital artery, posterior auricular artery, superficial temporal artery, and maxillary artery)


 * "Some Anatomists Like Fucking, Others Prefer S & M"

Biological groupings in taxonomy

 * (The letters stand for Kingdom, Phylum, Class, Order, Family, Genus, and Species.)


 * "Kings Play Chess On Fine Green Satin"
 * "Knights Play Chess On Fat Glass Stools"
 * "Kirsten Puts Cats Over Family Generally Speaking"
 * "King Phillip Came Over From Germany Soaked"
 * "Kids Playing Carelessly On Freeways Get Splattered"
 * Or, if you were feeling in a certain way, "Kinky People Can Often Find Good Sex
 * "Kids Playing Carelessly On Freeways Get Splattered"

DNA characteristics
Many biology students use the tune of "Row, Row, Row Your Boat" to assist in remembering the characteristics of DNA: '''We love DNA, Made of nucleotides, A phosphate, sugar and a base, Bonded down one side. Adenine and Thymine, Make a lovely pair, Guanine without Cytosine, Would be rather bare. '''

Chemistry
Potassium, Sodium, Calcium, Magnesium, Aluminium, Carbon, Zinc, Iron, Tin, Lead, Hydrogen, Copper, Silver, Gold, Platinum. Or maybe this is too long winded. Alternatively, Lithium and Mercury may also be included: Peter's Simple Little Cousin Met a Crazy Zulu In The Lonely Hut Carrying Money: Silver, Gold, Platinum.
 * Chemistry students use the phrase "LEO says GER" to keep the two halves of a redox process straight, since the Loss of Electrons is Oxidation while the Gain of Electrons is Reduction. Another version is the word "OIL-RIG", meaning Oxidation Is Loss, Reduction Is Gain (of electrons).
 * The first few elements of the Periodic Table can be remembered with "Harry He Likes Beer But Can Not Obtain Food".
 * A longer version, covering the elements from Helium to Potassium, is "Here Lies Benjamin Bold; Cry Not Old Friend; Needlessly Nature Magnifies All Simple People Sometimes, Clots and Kings." Skipping Calcium, the subsequent elements from Scandium to Zinc (the first  group of transition metals) can be remembered via "Scandinavian T V Corrupts Many French Coalmen's Nieces and Cousins (Cu Zins)".
 * The universal gas constant "PV/T" was remembered in the 1960's by saying "Pee" "Vee" over the "Telephone". Pee Vee was a television character in the 1960s that was always talking on the telephone.
 * The Reactivity series can be remembered thus. Poisonous Snakes Can Make All Cats Zippy In The Lost House Capturing Special G Ps
 * The three elements that when combined with Hydrogen form Hyrdrogen Bonds, can be memorized by the following saying: "Hydrogens just want to have FON (Flourine, Oxygen, and Nitrogen)" This saying is loosely based off the song "Girls Just Want to Have Fun" by Cyndi Lauper.
 * Diatomic elements can be memorized by using the phrase "Count HOFBrINCl" and also by the phrase "Have No Fear Of Ice Cold Beer"(Hydrogen, Oxygen, Flourine, Bromine, Iodine, Nitrogen, and Chlorine).

Electronics
To help remember the color code that is used to identify the value of electronic resistors, the following phrase was in common use in electronics training in the US Navy: "Bad Boys Rape Our Young Girls Behind Victory Garden Walls". The letters correspond to the colors black, brown, red, orange, yellow, green, blue, violet, grey, and white, which in turn correspond to the digits 0-9.

In the network design OSI model, the seven layers (Physical, Data link, Network, Transport, Session, Presentation, and Application) can be remembered with the mnemonics:

Please Do Not Throw Sausage Pizza Away

or

Princess Diana Nice Tits Seriously Pert Arse

Or in this one (Which starts from Application -> Physical) All People Seem To Need Data Processing

When wanting to know whether an electronic element in a circuit is a capacitor or an inductor when using AC power and all the information you are given is the phase angles of current I and voltage E, remember the name ELI ICE (Or ELI The ICE Man). This phrase means that your voltage E leads the current I in an inductor L, whereas current I leads the voltage E in a capacitor C. This method is commonly used among the U.S. Military.

Engineering

 * A mnemonic to remember which way to turn common (right handed) screws and nuts, including light bulbs, is "Righty tighty, lefty loosey."  An alternative is to remember that cLockwise has an L (for loosen), while counTer-clockwise (and anTi-clockwise in Britain) has a "T" (for tighten); this mnemonic must therefore be reversed to get the proper direction.

Geology

 * Geological time scale
 * The full mnemonic can be broken down to recall each of the epochs.
 * Camels Often Sit Down Carefully Perhaps Their Joints Creak Possibly Easing Oil May Prove Positively Helpful.
 * Paleozoic
 * Camels Often Sit Down Carefully Perhaps
 * Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Permian.
 * Mesozoic
 * Their Joints Creak
 * Triassic, Jurassic, Cretaceous.
 * Cenozoic
 * Possibly Easing Oil May Prove Positively Helpful.
 * Paleocene, Eocene, Oligocene, Miocene, Pliocene, Pleistocene Holocene.


 * Mohs scale of mineral hardness
 * Tall Girls Can Flirt And Other Queer Things Can Do
 * Talc, Gypsum, Calcite, Fluorite, Apatite, Orthoclase, Quartz, Topaz, Corundum, Diamond.


 * Remember Stalagmites vs Stalactites
 * stalagmites - G: ground - mite: might reach the roof
 * stalactites - C: ceiling - tite: have to hang on tight or will fall off

Mathematics

 * See also: Trigonometry mnemonics


 * Many mnemonics have been devised for remembering the digits of pi, consisting of phrases or verses in which successive digits of pi are obtained by counting the number of letters in each word. (Fortunately, the first thirty digits of pi contain no zeroes). Some are:
 * "How I wish I could recollect pi easily today." (3.14159 265)
 * "How I want a drink, alcoholic of course, after the heavy lectures involving quantum mechanics!" (3.14159 265358979)
 * (Alternate version of previous) "How I need a drink, alcoholic in nature, after the heavy lectures involving quantum mechanics!" (3.14159 265358979)
 * The following sonnet is a mnemonic for pi in iambic pentameter:

Now I defy a tenet gallantly

Of circle canon law: these integers

Importing circles' quotients are, we see,

Unwieldy long series of cockle burs

Put all together, get no clarity;

Mnemonics shan't describeth so reformed

Creating, with a grammercy plainly,

A sonnet liberated yet conformed.

Strangely, the queer'st rules I manipulate

Being followéd, do facilitate

Whimsical musings from geometric bard.

This poesy, unabashed as it's distressed,

Evolvéd coherent - a simple test,

Discov'ring poetry no numerals jarred.

Or, as popularized at Cincinnati's, they use the simple phrase Sally Can Tell : Oscar Has A Hard On Always. (It's been theorized that mnemonic devices that reference strong emotions, such as sexual feelings, imprint a stronger memory. However "Hat On" works equally well, but seems to be less memorable.) Another phrase used in English schools is Six Overweight Heffalumps Came And Heavily Trod On Arthur. Oscar Had A Heap Of Apples also works if you can remember the sine, cosine, tangent order.
 * See "Poe, E.: Near a Raven" for an extreme example.
 * Two mnemonics for the constant e (the base for natural logarithms) are "We require a mnemonic to remember e whenever we scribble math" and "To express e, remember to memorize a sentence to simplify this". The lengths of the words constitute the number 2.7182818284, an approximation of e to 10 decimal places.
 * Another mnemonic for e is 2.7-Andrew Jackson-Andrew Jackson-Isoceles Right Triangle. Andrew Jackson was elected president in 1828, and the next digits, 45-90-45, may be thought of as the three angles of an Isoceles Right Triangle. This gives e to 15 places, 2.718281828459045.
 * Many people remember the order of operations in arithmetic with the word Brackets Of (fractions: 1/2 of 2) Division Multiplication Addition Subtraction (BODMAS or BOMDAS). In the United States, students often use the sentence Please Excuse My Dear Aunt Sally, where the E signifies exponentiation. Occasionally the phrase is modified to My Dear Mother's Aunt Sally, with the second M standing for modulo; this is more often seen in the context of programming languages, where the modulo operation is more common.
 * Many secondary school students remember the basic trigonometric functions with the phrase SOH-CAH-TOA (pronounced "soak a toe-uh"). SOH ... Sine = Opposite leg divided by the Hypotenuse CAH ... Cosine = Adjacent leg divided by the Hypotenuse TOA ... Tangent = Opposite leg divided by the Adjacent leg *A much sportier way to remember it is with the phrase:
 * Saddle Our Horses, Canter Away Happily Toward Other Adventures.
 * "One Hopes, And Hopes, On America" was widely taught to British schoolchildren during World War II (the sine-cosine-tangent order was presumed). Not only was it a good mnemonic, it also served to reassure the children that Great Britain was not doomed to Nazi annihilation.


 * For remembering the order of taking the derivative of a quotient in calculus, the phrase "ho-di-hi, hi-di-ho, hoho" can be useful, where ho means the bottom, hi means the top, and di means the derivative. So, d(a/b)/dx = (b da/dx - a db/dx)/b^2

Physics

 * The fake name Roy G. Biv helps us to remember the order of the colors in the spectrum. In England "Richard Of York Gave Battle In Vain" is popular (Red, Orange, Yellow, Green, Blue, Indigo, Violet). In an alternate version, "Battle" is replaced with "Birth".
 * A mnemonic used by physics students to remember the Maxwell relations in thermodynamics is "Good Physicists Have Studied Under Very Fine Teachers", which helps them remember the order of the variables in the square, in clockwise direction. Another mnemonic used here is "Valid Facts and Theoretical Understanding Generate Solutions to Hard Problems", which gives the letter in the normal left to right writing direction.
 * The Group XVIII inert gases (helium, neon, argon, krypton, xenon and radon) may be recalled by the sentence "Heaven Never Arsked Kriegspiel's eXtra Rent"
 * The phrase "We guarantee certainty, clearly referring to this light mnemonic." represents the speed of light in meters per second through the number of letters in each word: 299792458.

General knowledge

 * "DOC" represents phases of the Moon by shape: "D" is the waxing moon; "O" the full moon; and "C" the waning moon. In the Southern hemisphere, this is reversed, and the mnemonic is "COD". A French mnemonic is that the waxing moon at its first "premier" quarter phase looks like a 'p', and the waning moon at its last "dernier" quarter looks like a 'd'. In German, the Moon is compared to a handwritten small letter a for "Abnehmen" (waning) and a z for "Zunehmen" (waxing). One more (Northern hemisphere) mnemonic, which works for most Romance languages, says that the Moon is a liar: it spells "C", as in crescere (Italian for "to grow") when it wanes, and "D" as in decrescere ("decrease") when it waxes.
 * "Red, right, return" used to remember which sea mark denotes which side of a sailing channel.
 * On the other hand, "there´s always some red port (wine) left" is also used to remember the basics in sea faring.
 * Let's not forget the word that reminds us that the best plan is usually a simple plan: K-I-S-S (Keep it Simple, Stupid!)

Geography

 * Many young Australian, Kiwi and British children remember the compass points in order in clockwise with the phrase Never Eat Soggy Weet-bix, or Never Eat Shredded Wheat (North, East, South, West). Weet-bix and Shredded Wheat are popular breakfast cereals in Australia, New Zealand and Britain. Another variation is Never Ever Smoke Weed. In the United States, school children are often taught with the phrase Never Eat Soggy Waffles or Never Eat Sour Worms, whereas a Canadian rendition is Never Eat Soggy Wieners.
 * The acronym HOMES is also a mnemonic aid that can be used to remember the names of the North American Great Lakes (Huron, Ontario, Michigan, Erie, Superior). SMHEO is also useful to remember their positions from North to South, "Super Man Helps Every One" to remember their positions from West to East, and if you like, "Sam's Horse Must Eat Oats" helps one to remember their ordering by size from largest to smallest. The Canadian lakes can be noted as SHOE.(See if you can find others!)
 * The Dutch Antilles can be remembered by thinking of the Leeward Islands as the ABC islands and of the Windward Islands as the SSS islands.
 * Note: The SSS islands are part of what are in English called the Leeward Islands, but in e.g. French, Spanish, German, Dutch and the English spoken locally these are considered part of the Windward Islands.
 * The nations of Central America can be remembered (in order north to south) by "Better Go Home Every Night Completely Paid".(Belize, Guatemala, Honduras, El Salvador, Nicaragua, Costa Rica, Panama)
 * To help remember whether you lose time or gain it,: EWG and WEL. East to West Gains and West to East Loses
 * How to set your clock to accommodate the shift to and from daylight savings time: "Spring forward. Fall back."

Military

 * A mnemonic to remember different ranks of generals in the U.S. Military is "Be My Little General" for Brigadier General (one star), Major General (two stars), Lieutenant General (three stars), and General (four stars).

Music

 * Beginning music students trying to memorize the notes of the staff using the mnemonics "Every Good Boy Does Fine", "Empty Garbage Before Dad Freaks", "Every Good Boy Deserves Fudge" (or, in Britain, "Every Good Boy Deserves Favour" - also the title of a play with music by Tom Stoppard and Andre Previn), and "FACE" for the lines and spaces of the Treble Clef respectively.  The Bass Clef equivalents are "Good Boys Do Fine Always" or "Good Boys Deserve Fine Apples" or "Great Big Dogs Fight A lot" for lines, and "All Cows Eat Grass" or "All Cars Eat Gas" for spaces.
 * Note: This method of "remembering" note positions on treble and bass clefs will lead to problems later on in music study. It is much better to learn the note positions on the grand staff as a whole and regard the treble and bass clefs as markers.
 * The strings on a six-string guitar with standard tuning can be remembered using the mnemonics: "Elephants And Donkeys Grow Big Ears",
 * The circle of fifths can be remembered using the mnemonic Forty Cats Going Down An Empty Barrel.
 * The spelling of 'Rhythm' can be remembered as "Rhythm Helps Your Two Hips Move."
 * If the student wants to remember the order in which sharps go, i.e. F# then F# and C# then F# and C# and G#. The mnemonic is "Father Christmas Gave Dad An Electric Blanket". Similarly if they wish to remember the order of the flats, the mnemonics -"BEAD Glass Cuts Fingers," "Blanket Explodes And Dad Gets Cold Feet" and "Battle Ends And Down Goes Charles' Father", are used. Handily, when reversed, this creates the sharps list.

The calendar

 * The rhyme Thirty days hath September is commonly used as a mnemonic for the number of days in the months of the year. If the rhyme is too much effort, then it might be sufficient to remember that July is named for Julius Caesar, and that August is named for Augustus Caesar, both of whom were emporers of acient Rome.  Thus, the emporers were entitled by fiat to have a 31 day month, and the rest of the months fall into an alternating 30-31 pattern, with the exception of Februrary, which at one time was the last month of the year!  Thus proceeding as if March was the beginning of the year, the month of September becomes the seventh month, October the eighth month, November the ninth month and December the tenth month, in accordance with the Latin prefixes from which the names of these months are derived.  Thus March, April, May, June, and July belong to Julius Caesar and have a 31-30-31-30-31 pattern.  Likewise August, September, October, November and December are associated with Augustus Casear and form a second 31-30-31-30-31 pattern.  January, associated with the less memorable Janus, was once along with February at the end of the year, but now these two months form another pattern that starts with 31, but which is then terminated at the end of February, which by the original Roman calendar would have begun a new year.


 * Another mnemonic for the days of the months is not a rhyme or a jingle, but a gestalt. Whereas the traditional mnemonic simply associates the name of the month with the number of days, this one emphasizes the sequence. The 31 and less-than-31-day months would be easy to remember if they simply alternated, but the pattern of month lengths is not that simple. They alternate until the fourth 31-day month, July, which is immediately followed by another 31-day month. Since the human hand has four fingers, one can, given an appropriate mind-set, perceive this pattern in a view of the knuckles of two fists, held together. The raised knuckles can be seen as the 31-day months, the dips between them as the 30-day-months-and-February, and the gap between the hands ignored. (Thus: left-hand-pinky-knuckle = January, dip = February, left-hand-ring-knuckle = March, dip = April, and so on to left-hand-index-knuckle = July; then continue with right-hand-index-knuckle = August, dip = September, etc).
 * [[Image:knucklemnemonic.jpg|400px|Knuckle mnemonic]]


 * The dominical letters for the years 1630, 1730, 1830, and 1930, taken in that order, spell "FACE". This can be remembered by the mnemonic "dirty face" (for "'30 FACE").

Anamonics (Scrabble)
Many tournament Scrabble players employ anamonics, a form of initialization mnemonic, for the purposes of learning and quickly recalling sets of acceptable words. An anamonic consists of a "stem" (usually of six or seven letters), paired with a semantically related phrase, in which each letter of the phrase can be added to the stem and rearranged to form at least one acceptable word. For example, if a player has the tiles ACDEIRT on her rack, and recalls the anamonic "DICE-ART = casino math diploma", she will know precisely which letters may be played through to form 8-letter words, and will hopefully be aided in finding the words: ACCREDIT, RADICATE, ACRIDEST, RATICIDE, DICENTRA, CERATOID, TIMECARD, CITRATED/TETRACID/TETRADIC, TRACHEID, READDICT, PICRATED, and ARTICLED/LACERTID.

Other mnemonic systems

 * Mnemonic verses
 * Acronym System
 * Link System
 * Room System
 * Goroawase System

Arbitrariness of mnemonics
A curious characteristic of many memory systems is that mnemonic devices work despite being (or possibly because of being) illogical, arbitrary, and artistically flawed. "Roy" is a legitimate first name, but there is no actual surname "Biv" and of course the middle initial "G" is arbitrary. Why is "Roy G. Biv" easy to remember? Medical students never forget the arbitrary nationalities of the Finn and German. Any two of the three months ending in -ember would fit just as euphoniously as September and November in "Thirty days hath...", yet most people can remember the rhyme correctly for a lifetime after having heard it once, and are never troubled by doubts as to which two of the -ember months have thirty days. A bizarre arbitrary association may stick in the mind better than a logical one.

One reason for the effectiveness of seemingly arbitrary mnemonics is the grouping of information provided by the mnemonic. Just as US phone numbers group 10 digits into three groups, the name "Roy G. Biv" groups seven colors into two short names and an initial. Various studies (most notably The Magical Number Seven, Plus or Minus Two) have shown that the human brain is capable of remembering only a limited number of arbitrary items; grouping these items into chunks permits the brain to hold more of them in memory.

Assembly mnemonics
In assembly language a mnemonic is a code, usually from 1 to 5 letters, that represents an opcode, a number.

Programming in machine code, by supplying the computer with the numbers of the operations it must perform, can be quite a burden, because for every operation the corresponding number must be looked up or remembered. Looking up all numbers takes a lot of time, and mis-remembering a number may introduce computer bugs.

Therefore a set of mnemonics was devised. Each number was represented by an alphabetic code. So instead of entering the number corresponding to addition to add two numbers one can enter "add".

Although mnemonics differ between different CPU designs some are common, for instance: "sub" (subtract), "div" (divide), "add" (add) and "mul" (multiply).

This type of mnemonic is different from the ones listed above in that instead of a way to make remembering numbers easier, it is a way to make remembering numbers unnecessary (by relying on some external way to tie each mnemonic to a number).

History of mnemonics
See the method of loci.

Software
Mnemonic Moronimizer, Stupidity Reduction Device, patent pending, at http://pagesofmystery.com/
 * 010 Memorizer (commercial software for memorizing numbers)
 * 2Know - Windows Freeware for converting numbers to words using the Major System. Now in English, German, and French.
 * Random secure password generator with automatic mnemonic generation
 * Free software to help memorise Pi

Other

 * Memory Improvement techniques - Free online tutorials and forums, vedic maths guides, leaving cert and GCSE/A level memory tips too. All FREE!.
 * VTrain's Memory Aids - Useful tips on mnemonic techniques.
 * Flocabulary Rhyming mnemonics over Hip-Hop music to help students remember vocabulary words
 * AidToMemory.com, mnemonics collection and forum
 * Use mnemonics to learn English
 * Human Memory
 * Homepage of the World Memory Championships
 * Mick Curtis memory techniques A practical memory course.
 * Google Answers: How to Have a Good Memory
 * Memory Joggers Using Mnemonics to teach children Math
 * The Memory Page: Tutorials and tips on how to improve your memory.
 * Science mnemonics From Science Jokes
 * Mnemonic Moronimizer, Stupidity Reduction Device, patent pending, at http://pagesofmystery.com/


 * Tools for Improving Your Memory from Mind Tools
 * Method of loci about Memory Palaces
 * The Effect of the Integrated Keyword Method on Vocabulary Retention and Motivation by Dr. Joern Hauptmann
 * Medical Mnemonics.com: World's Database of Medical Mnemonics - "A free online searchable database of medical mnemonics to help students of health-related professions remember the important details."
 * Memory Improvement and Learning Information
 * Memory Master

Mnemotechnická pomůcka Mnemoteknik Merkspruch Mnemotechnik Mnémotechnique Ezelsbruggetje 記憶術 Mnemotechnika Mnemónica Mnemotehnika Minnesregel 助憶碼