Creating Graphs

What is a graph? Graph = a pictorial representation of a collection of data Graph = a pictorial representation of a collection of data

Why do we need GRAPHS? Used to show a relationship between two or more variables Used to show a relationship between two or more variables Read large amounts of information quickly Read large amounts of information quickly

What is data? How can data be reported? How can data be reported?

Data can be reported 3 main ways: 1. Paragraph form 2. Table form 3. Graph form

How are graphs labeled?

Title = top and centered Title = top and centered Should describe information as COMPLETELY as possible Should describe information as COMPLETELY as possible

How would you create a title for this graph?

X-axis = horizontal axis; describes the independent variable Describes the categories Describes the categories Includes UNITS Includes UNITS

What is described in the x-axis?

What are the units for the x-axis?

Y-axis = vertical axis; describes the dependent variable Label describes the amount/category Label describes the amount/category Includes UNITS Includes UNITS Uses an appropriate SCALE Uses an appropriate SCALE

What is the y-axis describing?

What are the units for the y-axis?

Variable = things that change in an experiment What are the variables illustrated in this graph? What are the variables illustrated in this graph?

What is the independent variable in this graph?

What is the dependent variable in this graph?

Scale = numerical step/amount that places the data in even increments Should suit ALL data points Should suit ALL data points Includes UNITS Includes UNITS Typically multiples of 2, 5, or 10 but this depends ENTIRELY on the data set! Typically multiples of 2, 5, or 10 but this depends ENTIRELY on the data set!

Scale = numerical step/amount that places the data in even increments What is the scale for this graph? What is the scale for this graph? Also keep in mind the min/max values for axes Also keep in mind the min/max values for axes

What is the scale for the y-axis?

What is the scale for the x-axis?

Time is almost always on the x-axis

Time = almost always shown on the x-axis

Variable – a change in the experiment Independent variable –changed for the purpose of the experiment  Graphed on x-axis Variables

Dependent variable = changes as a result of changing the independent variable  Graphed on the y-axis Variables

A farmer wants to test to see if the amount of fertilizer he gives his corn will impact the growth of his corn. What is the VARIABLE the farmer should change to test this experiment? What is the VARIABLE that may change as a result of the experiment?

Data can be reported 3 main ways: 1. Paragraph form 2. Table form 3. Graph form

Paragraph form (aka raw data) In the fall of 2010, Hardin Creek in Boone, NC was studied to measure the number of different amphibians living in the creek. Four species were observed living in the creek: Southern Cricket Frog (Acris gryllus) of which there were seven, Bullfrog (Rana catesbeiana) of which there were five, Marbled Salamander (Ambystoma opacum) of which there were five, and White-spotted Slimy Salamander (Plethodon cylindraceus) of which only one was observed.

Data Table form (organized data) Amphibian Common Name Scientific Name Number of Organisms Observed Southern Cricket Frog Acris gryllus7 BullfrogRana catesbeiana5 Marbled salamander Ambystoma opacum5 White-spotted salamander Plethodon cylindraceus 1

Graph form (analyzed data)

Answer the folowing using the graph below: Which amphibian was most abundant in fall of 2010 in Hardin creek? Which amphibian was most abundant in fall of 2010 in Hardin creek? What is the common name of the least abundant species? What is the common name of the least abundant species?

5 Types of Graphs 1. Bar graph 2. Pie graph or Pie Chart 3. Line graph 4. Scatterplot Graph 5. Population Graph

Using your lab notebook, collect the name, age, and elementary school of each person in this class. You have 3 minutes!

Bar Graph = shows data for each variable using bars Good for comparing amounts for different variables Good for comparing amounts for different variables

The number of freshmen in each major at Wabash College What is the Ind/Dep Variable? What is the Ind/Dep Variable? How many students are chemistry majors? How many students are chemistry majors? What is the total freshmen enrollment? What is the total freshmen enrollment?

The number of freshmen in each major at Wabash College How many students are majoring in economics? How many students are majoring in economics? How many more poly sci majors are there than psych majors? How many more poly sci majors are there than psych majors?

Using your class data… Create a data table that compares these two variables: Create a data table that compares these two variables: Number of students from each elementary school Number of students from each elementary school

Using your class data… Create a BAR graph that compares: Create a BAR graph that compares: Number of students from each elementary school Number of students from each elementary school

Pie Graph = (aka pie chart) shows data as part of a whole Good for showing percentages Good for showing percentages

What is the ind/dep variable? What is the ind/dep variable? What percent of the day is spent watching TV? What percent of the day is spent watching TV? How many hours are spent sleeping? How many hours are spent sleeping? What activity takes up the least amount of time? What activity takes up the least amount of time? The graph below represents the typical day of a teenager.

What activity takes up a quarter of the day? What activity takes up a quarter of the day? What two activities take up 50% of the day? What two activities take up 50% of the day? What two activities take up 25% of the day What two activities take up 25% of the day The graph below represents the typical day of a teenager.

Using your class data… Create a data table that compares these two variables: Create a data table that compares these two variables: Percentage of students from each elementary school (round to nearest 1%) Percentage of students from each elementary school (round to nearest 1%) Percent= (part / whole) * 100 Percent= (part / whole) * 100 Percent from BR = (6/24)*100 Percent from BR = (6/24)*100 = (1/4)*100 = 25%

Line Graph = Shows data by plotting dots and connecting dots to show a trend  Good to use when showing change over time.

What is the ind/dep variable? What is the ind/dep variable? How many total miles did the car travel? How many total miles did the car travel? Describe the motion of the car between hours 5 and 12? Describe the motion of the car between hours 5 and 12? What was the average speed of the car for the trip? What was the average speed of the car for the trip?

Scatterplot graph = compares two points (x,y) to show a trend Scattering of points will demonstrate a trend Scattering of points will demonstrate a trend

What is missing in this graph? What is missing in this graph? Is this a linear or exponential correlation? Is this a linear or exponential correlation? Write a statement about this graph’s trend Write a statement about this graph’s trend

How is correlation different from causation?

Correlation= when one variable occurs alongside another

Causation = when one variable directly influences/causes another

Population Graphs = show the age structure of a population

Which group makes up the largest percentage of the population?

What does the graph indicate about the future growth in each country?