Polish your plan!After shopping around for a science-project idea (see p. 8), you decide to experiment with something you can sink your teeth into. How about ... toothpaste toothpaste, n See dentifrice. ?! With dozens of toothpaste brands Popular toothpaste brands in the United States include:
Say you decide to test three popular brands of toothpaste: Brite White, Mint City, and Toothy Delight. The first thing you'll need to do is set up a procedure, a plan you can follow to get some fresh results. Hmmmm. With this procedure, you end up with three sets of toothpaste-smeared teeth. What could be wrong? Your procedure may have some "cavities" in it. Ask yourself: Would two people reading this procedure do the same experiment? Not likely. The procedure lacks some important details, like how much toothpaste to use and how long to brush. Here's a checklist that may help you polish your procedure: * Try to visualize the procedure from start to finish. * Begin with a list of materials. * Include amounts or measurements for each material, where necessary. * In general, test only one independent variable at a time. * Keep all other variables constant (unchanged) for each trial. Otherwise, your results will be unreliable. * Always include a control, a test subject that can be used for comparison. * Conduct repeated trials to verify (1) To prove the correctness of data. (2) In data entry operations, to compare the keystrokes of a second operator with the data entered by the first operator to ensure that the data were typed in accurately. See validate. your results. Your new and improved procedure might look something like this: PASTY PROCEDURE A: 1 Squirt a sample of each toothpaste on three toothbrushes. 2 Stain Stain (microbiology) Any colored, organic compound, usually called dye, used to stain tissues, cells, cell components, or cell contents. The dye may be natural or synthetic. The object stained is called the substrate. three sets of dentures (false teeth) with a splash of grape juice. (Your dentist dentist /den·tist/ (den´tist) a person with a degree in dentistry and authorized to practice dentistry. den·tist n. A person who is trained and licensed to practice dentistry. might be able to lend you some unused dentures. If not, use white floor tiles, stones, or another toothlike substance. 3 Start to brush. 4 Compare your results. PASTY PROCEDURE B WHAT YOU NEED: three brands of toothpaste * four sets of dentures or white floor tiles or equal-size stones) * permanent markers A permanent marker is a type of marker pen that is used to create permanent writing on an object. Generally the liquid is water resistant, contains the toxic chemical xylene or toluene, and is capable of writing on a variety of surfaces from paper to metal to stone. * two clear glasses * 750ml (3 cups) grape juice * 750ml (3 cups) water * watch with second hand * toothbrush toothbrush, n a handheld device with an arrangement of bristles at one end, and a handle designed to reach effectively all exposed surfaces of the teeth and gingiva. * metric ruler * paper towels * "Stain Scale" (opposite page) WHAT TO DO: 1 Label the three toothpaste brands and the three sets of dentures A, B, and C. Label a fourth set of dentures D. That one will be the control, the one that remains clean for comparison. 2 Pour 250ml (1 cup) grape juke into a clean glass. Pour 250 ml (1 cup) water into second glass and set aside. 3 Soak Denture denture, artificial replacement for natural teeth and surrounding tissue. Dentures are classified as partial or complete. The former are removable and maintained by clasps, or are fixed bridges with crowns cemented over adjacent teeth or over spikes embedded in the A in grape juice for 15 minutes. 4 Place a 1.5 cm-long squirt of Toothpaste A on a clean toothbrush. Vigorously brush Denture A for 20 seconds, moving from teeth on left side to teeth on right side. 5 Rinse Denture A in water glass for 10 seconds. Hold dentures up to the "Stain Scale," observe color, and record results. STAIN SCALE 5 4 3 2 1 bad medium pearly stain stain white 6 Repeat Steps 2 through 5 twice more for Toothpaste A and Denture A (to verify your results). 7 Repeat Steps 2 through 6 for remaining toothpastes and dentures (excluding D), one at a time. Compare and graph results for Dentures A through D. Next, run your new procedure by an "expert"--a teacher, parent, or friend--to see if they can spot any holes or if they can imagine each step of the procedure. (I asked my dentist to check Pasty Procedure B, above. He gave me a free neon neon (nē`ŏn) [Gr.,=new], gaseous chemical element; symbol Ne; at. no. 10; at. wt. 20.179; m.p. −248.67°C;; b.p. −246.048°C;; density 0.8999 grams per liter at STP; valence 0. Neon is a colorless, odorless, and tasteless gas. spider ring for my success!) The key to a good procedure is to write it up so that anyone can repeat the experiment exactly. Chances are, you may have to add more details here and there to make the procedure even more precise. For instance, you might want to standardize stan·dard·ize v. 1. To cause to conform to a standard. 2. To evaluate by comparing with a standard. how hard you brush each set of dentures, or how you brush--up and down, side to side, or in a circular motion In physics, circular motion is rotation along a circle: a circular path or a circular orbit. The rotation around a fixed axis of a three-dimensional body involves circular motion of its parts. . With these guidelines guidelines, n.pl a set of standards, criteria, or specifications to be used or followed in the performance of certain tasks. in mind, why not practice writing up a procedure for other toothpaste tests. For example: Which toothpaste leaves you with the freshest breath? Which toothpaste dispenser makes the biggest mess? Which brands give you the most brushing for your money? When you think you've got it down, give your procedure a trial run. Remember, you can always scrub it and start over. |
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