9-19-2017 Repetition and Replication Intro

Do Now: Answer these questions in your Science Notebook You are on the basketball team and your coach feels you have what it takes to be a professional athlete. Every day he makes you do the same drills over and over for practice. You stand in the same spot and practice shooting through the hoop, each time doing it the same way. How do the repeated practice drills (repetition) improve your ability to get the ball in the hoop? If you were the coach, how could you train another player to copy your technique (replication) so they can be as successful at making the basket each time?

Tonight’s Homework: Study for Quiz on Wednesday, 9/20 Turn in your homework

Repetition vs. Replication Take notes in your science notebook

Repetition in Science When you do many trials in science, you are repeating your own experiment over and over. Making multiple sets of measurements or observations in a scientific investigation. Running through the experiment and collecting data more than once. Why do we do multiple trials within experiments? It helps us better approximate the true value of what we are measuring and account for variability.

What happens if you do too few trials? Take a coin toss for example. Based on your experience, what are the chances that when you flip a coin it will land on heads? 50% - there is a 1 out of 2 chance of a coin landing on heads. This means that we could predict to get heads about 50% of the time in a coin toss. If we only do one coin toss, there is no way to get 50% in this situation. With only one trial, you’d either get heads or not get heads, so your result would be either 100% or 0%. That’s not very close to the predicted outcome!

Take a look at how close we can get to 50% if we increase the number of coin tosses, or trials. Notice for each example that we are one flip away from a 50/50 results. As we increase the number of trials, our heads percentage gets closer and closer to 50. Number of Trials Heads Tails % Heads 3 2 1 66% 5 60% 10 6 4 20 11 9 55% 50 26 24 52% 100 51 49 51% 1000 501 499 50.1%

Replication in Science Having an experiment repeated by others. Someone else should be able to follow your procedure to see if they can get the same results.

Replication Example Have you ever tried to cook an omelet? You have to follow the instructions, or procedure, in a recipe very carefully in order for it to turn out well. If you decide to take some shortcuts by skipping a few ingredients and not worrying about following the recipe, it can turn out disgusting.

Replication Example Follow verbal directions No questions! Do not look at your neighbor’s paper

Did your drawing look like this? Did your drawing look like this? What do you think happened? © copyright 2014-all rights reserved www.cpalms.org

Tell me about the process . . . How did you feel? Was it effective? Was it worthwhile? How could it be improved? Would being able to ask questions help? Would getting more details helped?

Okay, here are more details… Move your writing instrument ~3 inches down from the apex of the folio and render a small annulus. From the base of the annulus, generate a descendent stroke toward the central region of the sheet Did these details help? No, because the vocabulary was difficult to understand. Your procedures should be clear and easy to understand.

4 Corners Practice: Repetition Which of the following statements best describes repetition in an experiment? Doing many trials in your experiment Doing many different experiments about the same topic Sharing your results with many different people Having other people do your experiment

4 Corners Practice: Repetition Which of the following statements best describes repetition in an experiment? Doing many trials in your experiment CORRECT Doing many different experiments about the same topic Sharing your results with many different people Having other people do your experiment

4 Corners Practice: Replication Which of the following statements best describes replication in an experiment? Doing many trials in your experiment Other scientists doing your experiment with your procedure Doing many different experiments about the same topic Sharing your results with many different groups

4 Corners Practice: Replication Which of the following statements best describes replication in an experiment? Doing many trials in your experiment Other scientists doing your experiment with your procedure CORRECT Doing many different experiments about the same topic Sharing your results with many different groups

Exit Ticket: On a notecard, state if each scenario is an example of repetition or replication Tom measured the distance of a ramp. He then rolled a marble down the inclined surface ten times and recorded the time it took the marble to reach the bottom. A scientist discovered a new substance that cured diabetes in a rat. This substance was tested by 100 other scientists with the same result. Lizzette is investigating the effects of sunlight on plant growth. Every day for 2 weeks she puts a plant outside for 10 hours. She measures the plant's height daily at noon and records the data in her journal. Jerry bounces a ball, dropping it from the same height and using the same force each time. He does this on a flat concrete surface 3 times and records how high the ball bounced each time in his notebook. He then repeats the experiment on a carpeted surface and a dirt surface, each time doing 3 trials. Kurex Labs is testing a new cancer medication in the United States, Italy, and China. Each testing facility will provide 100 patients with the new treatment for 3 months. Lab personnel will document the medication's effectiveness.