What Makes a Good Graph ** YOUR GRAPH TELLS A STORY, IT SHOULD STAND ALONE AND A STRANGER SHOULD BE ABLE TO LOOK AT IT AND UNDERSTAND THE “STORY” BEING TOLD. ** 2010 – Collecting Data 1

1. NEATNESS COUNTS use a pencil!, graph paper, a ruler to produce neat, accurate graphs (colors are nice!) Easy to read  easy to grade!! 2

2. Must have a TITLE Descriptive title - Always give your graph a title in the following form: "The dependence of (your dependent variable) on (your independent variable). Let's say that you're doing a graph where you're studying the effect of temperature on the speed of a reaction. In this reaction, you're changing the temperature to known values, temperature is your independent variable. Because you don't know the speed of the reaction and speed depends on the temperature, the speed of the reaction is your dependent variable. As a result, the title of your graph will be "The dependence of reaction rate on temperature" 3

3. What are your AXES Y (vertical axis): dependent variable → measures or frequency (i.e. counts, %) dependent variable changes or is manipulated X: (horizontal axis): independent variable → distribution (i.e. time, categories) For the graph described above, temperature would be on the x-axis (the one on the bottom of the graph), and the reaction rate would be on the y-axis (the one on the side of the graph) 4

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4. What are your UNITS? Y and X are uniform / uncluttered, having units and labels If you don’t have units we do not know what you are talking about!! Proper Scale (0,5, 10, 15)not ( 2, 10, 22, 30) 6

5. Key and Legend Key to identify your sets of Data Legend to tell: who, what, when, where, and how 7

Line Graphs Visually displays values, usually over time to show trends Best way to plot multiple sets of data for comparison Implies continuous data (i.e. time) ** Best Choice ** 8

Bar Graphs Emphasizes magnitudes more than percentages or differences Can plot multiples sets of data (series) for comparison Implies discrete data (i.e. letter grades, hair color) Best for comparing categories 9

Pie Graphs Compares relative magnitudes or frequencies Can plot only a single set of data Shows the percentage an item contributes to the whole 10

Grades vs. hours of sleep for two science clases at Charles W. Flanagan High School, Pembroke Pines, FL,

What is Wrong With this Graph? 12

What is Should Look Like 13

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