Are the following statements true or false? (a) The variance of a random variable is measured in the same units as the random variable. (b) In a diving competition, the scores awarded by judges for a particular type of dive have an expected value of 78 with a standard deviation of 5. If the scores are doubled so that they can be compared with scores fromaneasiertypeofdive,thenewscoreswillhavean expected value of 156 and a standard deviation of 10. (c) The variance of the difference between two independent random variables cannot be smaller than the larger of their two variances. (d) If a continuous random variable has a symmetric probability density function, then the mean and the median are identical. (e) If X is a continuous random variable, then P(X x) = P(X > x) for any value of x. (f) If X is a discrete random variable, then P(X x) = P(X > x) for any value of x.
Jenny Lundberg CI427—Mohr April 9, 2016 Class Notes Agenda 1. Cookbook vs Inquiry revisited 3. FACTs Presentation 3. Workshop 4. Collaboration 5. Check In/Up Time Cookbook vs Inquiry revisited Article: Inquiry On Board (October 2006) My personal Notes: o Brainstorm As a class, discuss possible variables that can be seen in a specific experiment. o Choose Variable Manipulated variable (independent variable) Responding variable (dependent variable) Controlled variables o Ask a Question Question is tied to the manipulated variable o Predict and Outcome Teacher models how to form a prediction Students need to justify their thinking o Set up Experiment Use an inquiry board to organize and sequence how they would like to organize the experiment. Limit students to one experiment of inquiry. Use diagrams in journals to keep them understanding and tracking their experiment. o Table of Results Record observations. Create data table. The effect of the manipulated variable isn’t known yet. o Look for Patterns and Graph of Results Present information on a graph. The visual will help students to answer their question. o Answer the Question The answer is found between the data and the graph Class discussion: o Reviews the scientific method and how you might use it in the classroom. o Used manipulated and responding variables instead of independent and dependent variables. o The students are able to determine their own variables (open inquiry) instead of given the set of variables they must use (cookbook inquiry) o There is an importance of having multiple tests and tracking data. o Helps the students focus on variables instead of an experiment itself. The Four Question Research Strategy by Cothron, Giese and Rezba. Students and Research. 2000 Activity: The Grandfather’s Clock—Setting up Experiment Notes from the story o In the grandfather clock, you use the pendulum of the clock to keep the clock telling time by it swinging back and forth; ticktock. o Then a key is used once a week to wind and keep the pendulum going. o In the story, two weeks pass and the characters observe that the grandfather clock moves slower than a regular clock. o The character wants the clock to go faster! Character thinks: Maybe I need to swing the pendulum faster Maybe I need to give the pendulum less weight Maybe I need to shorten the length of the pendulum Setting up experiment, finding different variables to test: o Manipulating the mass (my group) o Manipulating the angle of the swing o Manipulating the string length Activity: The Crooked Swing—Make a Model Notes from the story o Problem is that the swing is crooked. o Variable: changing length of chains. Results: Same results. o Characters create a model and find out what made it go crooked. Setting up our models o Tie stings together and open into a Tformation. o Answers was that the strings had to be made the same length. (Although, the swing was now tilted and not parallel to the ground) Cookbook Lab: Investigating Pendulums Lab write up from Flinn. It gives the process and variables. Students would just follow directions and not make any natural inquiry to the process. FACTs Presentation Topic: Juicy Questions Stretch the students thinking so they look deeper for information to find an answer to a questions. It is usually a BIG question that will bring about smaller questions to guide students into finding the answer. Supports students learning. There is not necessarily just one right answer because students will access different parts of their schema when getting towards the answers. The teacher just needs to scaffold so that they students are going in the right direction of thought. Whole group collaboration bring a collection of knowledge and is beneficial for other students to hear one another’s thoughts. Example: “How does the water cycle work” A student may start asking questions about particular steps in the process to get the whole answer. We try it!: If a bowling ball and feather are dropped at the same time in a vacuum, what will hit the ground first YouTube Video: Brian Cox visits the world’s biggest vacuum chamber—Human Universe: Episode 4 Preview BBC Two If a student struggles, a teacher can prewrite a list of topics the students may need to consider before finding the way to the big question. Watching moon video of hammer and feather being dropped at the same time. The hammer and feather land at the same time! How do we explain gravity video. Clipped spandex represents matter in space and time. It shows how two objects being placed on the spandex will move closer and then next to one another when both placed on the spandex. The more mass there is, the bigger the pull is and the stronger the attraction is when new mass is added to the spandex. They show how things orbit by giving it a motion; it is discussed that in a vacuum, the orbit would have continued in a perpetual motion. Workshop Collaboration Time Splitting up responsibilities of what is left for the project. Check In/Up Times Upcoming Due Assignments Workshop due April 13 th Workshop practice/run through on April 16th Flinn Science Catalog Reference Manual 2013 All teachers in IL can get one for free. 18004521261 www.flinnsci.com This gives teachers the knowledge of possible hazards and ways to make the environment safe. Safety Data Sheets Found on the Flinn Scientific, Inc. Website o Go to teacheh resources o Click on “sign up for a free firstyear teacher’s survival kit” o Do middle school laboratory safety course Has a PDF that tells the 3 main duties: 1. The duty to instruct and warn. 2. The duty to supervise. 3. The duty to provide a safe learning environment. Labsafety.flinnsci.com/……… search in on Google. Poison Control number: 18002221222 Material Safety Data Sheets (MSDS)