Sunday, October 25, 2009

Testing The Magician's Fingers


A student from primary school where I studied came up and asked "Will you see the magic?" I like the tricks and uncovering those tricks of magic, hence requested her to illustrate the magic. She had brought box of color pencils with her.

I was asked to pick few color pencils while she turned such that I could see her back. She asked me to place those picked color pencils slowly in her left hand.

Later I was said to note down the color pencils which I have picked. And, I made note of those color pencils which appeared to me as red, green, black, blue, yellow and orange colors. After few seconds, I was asked to remove one color pencil from her left hand and place it in her right hand. It appeared as she was making sure that a color pencil was in her right hand. Later she moved it back to her left hand, where other color pencils were.

She instructed me to remember the color pencil which I have picked and placed in her right hand. And she asked me to move all the pencils in her left hand to box and close it. I had picked a color pencil which appeared to me as yellow-in-color and placed it in her right hand. Turning around she took the closed box in her hand and shuffled it with smile and confident. These actions of her made me more curious to observe her movements much more consciously.

She began to pick the color pencil by opening the box. She picked the pencil which appeared as pink-in-color and said not this. Later she picked the pencil that looked like brown-in-color and said not this. I kept looking at her eyes and body movements. Later she picked the pencil which looked as yellow-in-color and said this is your pencil.

I was surprised and sensed the trick here. And I believed my observations can be different if I closely investigate it. I asked her to repeat what she done. She was in full of joy and readily did illustrate her magic again.

I started my testing by stating test mission, "To uncover the illusion of little girl's magic trick."

Below are the questions that I gave for myself:
  • Do I know what should be tested, by modeling the magic trick that I witnessed just now?
  • What are the oracles and heuristics that can help me to know this magic trick?
  • What approaches and techniques should I be using in current and unexpected contexts to test, for revealing this magic trick?
  • How to configure, operate and observe the tests that I will be making?
  • How can I infer and perceive the test results?
  • How can I summarize my testing activities on revealing the illusion of magic trick?

While the little girl was illustrating the magic trick I was observing the possible suspicious (which acted as heuristics) moves which I thought of. Moving further in my tests, kept talking to the girl and varied my tests.

The information that I made note were as below while I varied my tests:
  • Was she able to see which color pencil I picked? She was not able to see it while I picked one color pencil from box.
  • What was the length and width of color pencil she was using to illustrate the magic? It was the pencil of length and width which was fitting in her palm.
  • What kind of traces does the color pencils leave behind when colored using it or touching the tip of its lead? The trace of color was bright enough to identify by me in this context.
  • How quick the traces of color can be erasable either on palms or on paper in this context?
  • Is this color trace visible to other person, if the little girl is away from the observer?
  • Am I biased here with anything here? Is it helping me? I was biased with information that color pencil will not leave any traces on palms on holding it.
  • Does the lead and body of the color pencil appear to be of same color?
  • What were the sequences of the pencil positions in the left hand of the girl?
  • What if I place pencil in alternate pattern such that head of one color pencil will see the lead of the other color pencil in left hand?
  • What if I change the position of color pencil head in the right hand of girl? Will she be still able to identify the color pencil I picked?
  • For what number of times the little girl can consistently identify the color pencil that I pick? And the girl should not clean her palms or hands on each time this trick is illustrated.
  • What if I place the same brand or manufacturers color pencil with broken lead, so that it cannot color unless it is sharpened to see the lead?
  • What if I place other brand or manufacturers color pencils in her hand? Will she be able to identify the one I pick?
  • What if I place pen with closed cap or colored objects in her hand that fits her palms? Will she be able to identify the one I pick?
  • Was there any embosses or any kinds of surface marks on color pencil, which could tell the color of pencil on touching it?
  • Did each color pencil have particular odor? If yes, how strong was that odor to identify uniquely? And this odor help her to identify the color pencil I picked?
  • What if I place the black lead pencil of same size to the color pencil in her hand? Will she be able to do the same gimmick as with color pencil she had bought?
  • What if I had smeared or rubbed the color pencil lead with other color pencil such that it gives two colors or a new color combination of the two? Will she have any difficulty now in identifying the color pencil I picked?
  • Does the color pencil's body will leave any color strains on the palm or fingers while it is held in hand? If yes, for what time period should a color pencil to be held in hand? For how long the color stains or traces from this will remain there?
  • Can I break the lead of a color pencil and can place the lead of other color pencil to it? How she can illustrate the same magic now?
  • What if I place color pencil, which appeared as its lead color and body color are not the same? Will she be able to pick the right color pencil now?
  • Were the color pencils are used earlier to color or yet to be used for coloring? Or it is used only for such trick purpose?
  • Did the box of color pencils had anything in it to make this trick happen?
  • What if I smear the oil or wax or water over her palms and fingers, before placing the color pencils in her hands? Will she be able to show her trick?
  • Will she be able to do the same trick using single hand and one finger, instead of both hands and its fingers?
  • How long and good the nails of her hands are? Did she make use of her nails too in this trick? Was nail polished with nail polish? If yes what was the color of it?
  • Had she smeared anything on her nails, palms and hands?
  • What all she is using to do this trick?
  • How quick the pencil will leave its strain if it is kept in hands?
  • What was the size of the lead of color pencil in the box?
  • What if I place the pencils all of same color in the box instead of those appears to be of different colors?
  • What if I closed her eyes by cloth so that she cannot see her hands or palms or fingers? And now I request her to pick the pencil. Will she able to do the trick now?
  • Was there any person who I did not see, helping her to say which color pencil I picked?
  • Was there any object around her that helped to see her which color pencil I picked? Did the direction she turned and stood have any influence or not?
  • Is she able to do this trick in any place and any time, apart from the place where she stood now?
  • What if I do not place the color pencil in her hand, instead keep an object that appears and feels like a color pencil but not a pencil? Will she be able to identify it or will she proceed further to say to put all the pencils back to box and be shocked to see no pencils in box?
  • How long did she keep the color pencil in her right hand? What time did she take each time to repeat when I asked her to illustrate, when I chose different color pencils?
These were few questions that I got during that context. Asked her to perform the trick for few times and showed that it can be different if tested. And her little thumb finger nail of right hand had color of pencil I picked, through which she identified. She left saying "cheating, you saw the magic on my nail."

Magic is also an art as testing is. Magic and testing can make the illusions and remove the illusions too. Both require skills, practices, explorations and failures to find alternative approaches that fit into the contexts.


Testing will show how our biases, anticipated, inferences, perceptions, investigations and the information we have will not be the same for any time.