Transcript Lesson 4
Graphing in Science: Presenting DATA What are graphs? - A graph is a visual way of presenting DATA. - It is one of the ways by which scientists communicate results. “A picture is worth a thousand words.” • Graphs are pictures that help us understand amounts. These amounts are called data. There are many kinds of graphs, each having special parts and used for specific reasons. KINDS OF GRAPHS 1. Circle Graph - is shaped like a circle [DUH!] . - It is divided into fractions that look like pieces of pie, so sometimes a circle graph is called a pie graph. - Many times the fractional parts are of different colors and a key that explains the diff. colored parts. Circle graphs show the relative amounts making up a whole. Try this! 1. Based on the graph, which gas accounts for most of the mass of our atmosphere? 2. Is Carbon dioxide a significant component of the atmosphere? 3. How does the amount of Oxygen compare with the amount of Nitrogen? composition by mass… 4. How might deforestation and the continuous burning of fossil fuels affect atmospheric composition as described by the chart? BAR GRAPH • A bar graph uses bars to show data. The bars can be vertical (up and down), or horizontal (across). The data can be in words or numbers. A bar graph is useful for displaying data sideby-side for comparison. Try this! Pay careful attention to the scale used! Know what is being compared! Start by reading the title- REALLY! From: Virginia State Released Test 3. A picture graph uses pictures or symbols to show data. One picture often stands for more than one unit so a key is necessary to understand the What could happen if you quantities. ignored the KEY in this pictograph? LINE GRAPH • A line graph shows points plotted on a graph. The points are then connected by a line. • Line graph shows trends. The trend can be… Steadily increasing Steadily decreasing CST spits out so many line graphs! 3. Look for a KEY and read it! Really! 1. It is very important to read the title- REALLY! 2. Pay attention to the AXES- REALLY! 4. Most importantly, look at trends! Are values going up? Going down? Running up and down? What is this graph trying to say? The motion of a toy car over time… Q1. Is the toy car moving at all? Q2. Did the car return to the same spot it started from? Q3. Describe the car’s motion from the 4th to the 10th s? 2008 Physical Science CST List 3 kinds of information this graph is conveying… What is the optimum percent of vitamin supplement that should be used to promote the biggest weight gain? Now…try this! Key is over here…Don’t forget! 2005 CST Biology Released Questions This graph looks weird! It’s still conveying information though! CST Biology, 2008