Pattern recognition and use in real life problem solving

Pattern recognition technique

Pattern recognition forms the basis of learning and action for all living things in nature.

Patterns are all around us - from human fingerprints, zebra crossings, warm current flows in oceans to the beautiful arrangement of a rose bud.

A baby begins to recognize various objects around it, learns how to react on events in its immediate environment and finally recognize, understand and respond to the words spoken to it - all by identifying patterns, associating the patterns with objects or concepts and use the concepts for responses leading to positive results.

Learning to speak in the language used in its immediate environment is one of the most difficult tasks effortlessly performed by every baby - that too without any teacher.

Pattern recognition and use continue throughout our lives. Our learning ability depends on how strong is our ability to identify a new useful pattern and use it suitably.

When a child goes to school first it learns new behavioral patterns to adapt to. When you take up a new position in your workplace, you have to acquire new patterns necessary for functioning effectively in the new position. Sometimes you change track in your career and go into a totally new but promising area. How can you be effective unless you learn all the required concept patterns in your new work domain?

We use the Pattern recognition technique all the time involuntarily and sometimes voluntarily or consciously in our daily life. When we navigate the city streets by car, we try to identify whether the streets are in a two axis grid or a star shaped formation. When we are to find a particular house in a street we see whether the numbers on one side of the street are even or odd, increasing or decreasing.

In emergent decision making situations of fire fighting or in a battle, the fighters don't have time to think, they must continuously act instinctively on the input patterns from the immediate environment and with the help of response patterns learnt through training, drills or earlier experiences embedded in their reflexes.

Pattern discovery in problem solving

Case example 1: Can you solve it?

Find the unit’s digit of $2^{23}$.

Before going through the solution, please try to solve the problem for 10 minutes.


At first thought you might want to use your calculator, but on second thoughts and being a problem solver, you will start analyzing the problem systematically instead. A problem solver adopts trial and error method, if at all, only as a last resort.

What actions are available to you? You know from experience that no calculator will take such a large calculation. Can you do anything else?

You examine the problem more closely and realize that full calculation is not to be done at all, only the single unit’s digit is to be found out. Now you have a clear and precise problem definition. This step is very important.  You are actually adopting a problem solver’s approach. You are not trying to solve the problem in any random way.

The main problem is now transformed to a simpler problem of finding one digit, and not the whole result of 2 to the power 23.

Searching for suitable further actions, and finding none that are obvious, you resort to the enumeration technique that can always be done by you. You start enumerating the results of $2^{1}$, $2^{2}$, $2^{3}$ and so on. A powerful principle of problem solving says,

If you find no promising action that can be taken at a stage except one, take that step and see what happens.

$2^{1} = 2$ with units digit 2, $2^{2} = 4$ with units digit 4,  $2^{3} = 8$ with digit 8, $2^{4} = 16$ with units digit 6, $2^{5} = 32$ with digit 2, $2^{6} = 64$ with digit 4.

Here you stop and form a conjecture that after every 4th power of 2, its units digit is repeating the same four values again. The all important 4-length repeating cycle of units digit values being, 2, 4, 8 and 6.

You test and verify your conjecture by calculating a few more powers of 2 and confirm that your conjecture was indeed right.

This is test and discovery of the repeating pattern of digits that is crucial to solving your problem.

The last step is easy. You divide 23 by 4, the length of the repeating cycle, getting remainder 3 and quotient 5. So, you clarify the situation in your mind, "units digit of $2^{23}$ will be the third value of the repeating 6th cycle of 2, 4, 8 and 6.

The answer is then 8.

In academic problems, specially in maths or reasoning where the problem solving capability of a candidate is tested, useful pattern discovery in the problems is vitally important.

We believe, pattern discovery is important not only in academic problem solving but also in dealing with complex real world problems. After all, patterns are so very integrated in every fabric of nature and human life, it should also be an important component of any real life problem. And if you can discover such a pattern in your problem, your problem understanding not only gets a big boost, problem solving using methods based on the pattern discovered comes within reach.

Pattern recognition in language understanding

Case example 2: Can you read it?

I cnduo't bvleiee taht I culod aulaclty uesdtannrd waht I was rdnaieg. Unisg the icndeblire pweor of the hmuan mnid, aocdcrnig to rseecrah at Cmabrigde Uinervtisy, it dseno't mttaer in waht oderr the lterets in a wrod are, the olny irpoamtnt tihng is taht the frsit and lsat ltteer be in the rhgit pclae. The rset can be a taotl mses and you can sitll raed it whoutit a pboerlm. Tihs is bucseae the huamn mnid deos not raed ervey ltteer by istlef, but the wrod as a wlohe. Aaznmig, huh? Yaeh and I awlyas tghhuot slelinpg was ipmorantt! See if yuor fdreins can raed tihs too.

This text appeared somewhere during late nineties and soon attained enormous popularity. Can you read it effortlessly? Most probably you can. The jumbling of the letters in the individual words pose no barrier to your recognizing the original words in the jumbled text.

As explained in the text, keeping the first and the last letter of every word untouched, all the other letters in every word have been scrambled randomly. But your mind ignores this scrambling and effortlessly identifies each of the words and continues to read the whole passage without any significant hitch.

Have you followed any special techniques or methods to achieve this seemingly impossible task? Nope. At least you don't know consciously of any such technique. You just read through.

This example shows inherent pattern recognition power of your mind in language understanding and is in the domain of Cognitive Science or Artificial Intelligence.

Case example 3: Can you read it?

This example has also used the same principle of letter scrambling, but with a twist. Please try it for some time. It is not easy. If you still are able to read the whole text correctly, then you must be having significantly higher pattern recognition power compared to common people like us.

The solution is given after the discussion on this text. Here goes the problem text.

Anidroccg to crad–cniyrrag lcitsiugnis planoissefors at an uemannd utisreviny in Bsitirh Cibmuloa, and crartnoy to the duoibus cmials of the ueticnd rcraeseh, a slpmie, macinahcel ioisrevnn of ianretnl cretcarahs araepps sneiciffut to csufnoe the eadyrevy oekoolnr.

The difficulty level of understanding the text has been increased significantly by introducing a pattern in the scrambling operation itself. It is no longer random. Can you discover this hidden pattern in scrambling of letters of each word keeping the first and last letters fixed?

In this case, you can take up the role of problem solver again, and examine suitable words to discover the fixed pattern of scrambling hidden in them. If you are able to find the pattern, you can immediately unscramble the whole text.

We find this example interesting as, using it you can test your

  • inherent pattern recognition ability in language understanding, and also
  • problem solving ability using pattern discovery.

Give it a serious try and then proceed with the solution.


Pattern: Instead of random scrambling, the letters between the first and the last were just inverted - a simple action resulting in powerful effect.

The original text is,

According to card-carrying linguistics professionals at an unnamed university in British Columbia, and contrary to the dubious claims of the uncited research, a simple, mechanical inversion of internal characters appears sufficient to confuse the everyday onlooker.

Examining this text further we notice that the words in the text are not very commonly encountered ones in everyday use - many of these are quite uncommon. This leads us to the first conjecture,

For understanding scrambled running text using inherent pattern recognition, familiarity with the words is essential.

At least once you should have seen a word to be able to unscramble it.

Analysing further, we notice that the degree of familiarity is an important factor in our ability to unscramble. Though trivial, we note this as our second conjecture,

Degree of familiarity increases the ease of unscrambling scrambled words using inherent pattern recognition.

Exploring further we ask, won't you find it easy to decipher a running text instead of a fragmented text? This is the area of meaning of the sentences as a whole, not just a few words carrying no meaning. This leads us to the third conjecture,

Associative meaning of the words together forming meaningful sentences helps understanding scrambled text using inherent pattern recognition.

Learning a language: Our experience supports this idea. When we read a novel, we encounter some words never seen before. From the meaning of the surrounding text we guess the meaning of the unknown words and form the vague idea as a concept in our mind. Later in another occasion when we encounter the word again, our mind automatically tests the validity of our concept about the word and either strengthens or weakens the belief on the concept earlier formed.

A sure way of learning a new language is to read its literature or long text that is especially interesting to you.

Coming back to the case example again, we now state our fourth conjecture.

The first case example of scrambled text is easier to understand because it used random shuffling of the letters inside two boundary letters in each word, whereas inversion of the lettters inside in the second case example increases the distance between a letter in scrambled word and its original position compared to the random shuffling. This increased distance created an increasing mismatch between the new pattern and the old pattern of a word and made the pattern matching activity more difficult.

At the end we need to reiterate, Pattern recognition and corresponding decision making are at the heart of human decision making. In most situations, this process is involuntary, but in many cases, we may be able to reach a just solution by explicitly searching for a pattern in the given problem world.

Most experts work on pattern recognition basis and most emergent decision making are basically pattern based and thus intuitive and instantaneous.

By working on your pattern recognition skills it should be possible for you to improve its power and so your ability to solve everyday problems.