Graphing Guide

What are you graphing? Systematic Observation or Experiment Not every investigation is an experiment, some are systematic observations Experiment Manipulating a variable to compare differences Which amount of Mentos will produce the highest stream when dropped in Diet Coke? Independent Dependent Systematic Observation Answering a question with a plan What happens when three Mentos are dropped in Diet Coke? Data is often qualitative, but can also be quantitative

Data Chart Great tool for data collection Drawbacks: Can be very large Year Enrollment (in mill) 2000 41.2 2001 42 2002 42.8 2003 43.5 2004 44.1 2005 44.8 2006 45.6 2007 46.1 2008 46.5 2009 46.9 2010 47.2 2011 47.7 2012 48.6 Great tool for data collection Drawbacks: Can be very large Difficult to see trends or relationships Cannot easily make predictions

Chart or Graph? Year Enrollment (in mill) 2000 41.2 2001 42 2002 42.8 2003 43.5 2004 44.1 2005 44.8 2006 45.6 2007 46.1 2008 46.5 2009 46.9 2010 47.2 2011 47.7 2012 48.6

Formulating a Graph Graphs compare two variables Independent variable: The variable the scientist manipulates; the “cause” e.g.: type of soda, type of mentos, number of mentos Put on X-axis Dependent variable: The variable that is measured; the outcome or data; the “effect” AKA outcome variable e.g.: Height of soda stream Put on Y-axis

Title: “Y as compared to X” What’s missing? Line of best fit -Ease of prediction -Derive equation Should display appropriate range Title: “Y as compared to X” Label Axis Include units Gridlines not always necessary Label Axis Include units

Types of Graphs A B C School district budget allotted to different departments Gas sales from each gas type Proportion of plant varieties at nursery Public school enrollment in the past 10 years Average price of gas from 2004-present Plant growth over a week Number of public universities in different US states Current gas prices at BP, Exxon, Shell, and Racetrac Final plant growth of plant grown in light and in dark Pie Chart Line Graph Bar Graph Compares divisions of a whole Reports percentages Compares variables over time Or over a spectrum of some sort Compares data that are in distinct groups or categories

Your Task Create graph of your group’s data Create graph of class data