Technical Science Scientific Tools and Methods Tables and Graphs

Tables and Graphs In this section you will … Use tables to organize information Construct circle graphs Construct bar graphs Construct line graphs

1 of 10 Using Tables Home Making observations and collecting information is large part of a scientist’s job. Once this information is collected it must be organized and presented in a clear and concise way. Tables and Graphs are the tools that scientists use to organize and present information.

2 of 10 Using Tables Tables consist of horizontal rows and vertical columns of information. Each row and column should have a heading that describes its contents. The table itself should have a title to describe its purpose. Identify the parts of the table on the following slide.

3 of 10 Using Tables Title Column Heading Row

Using Tables A table can hold a lot of information. 4 of 10 Imagine how long it would take to write out all the information in this table in sentences. A table allows you to present all of the information on a single page.

Using Tables Tables organize data efficiently. 5 of 10 Using Tables Tables organize data efficiently. All of the data regarding problems with the video system is in a single row. All of the data regarding software related problems is in a single column. The relationship between two variables is shown at the intersection of a row and column. The number of hardware problems with peripheral components is shown at the intersection of the hardware column and the peripheral row.

Using Tables Use the table to answer the following questions. 6 of 10 See if you notice a difference between the first two questions and the last two questions.

Using Tables Which system has the most hardware problems? 7 of 10 Using Tables Which system has the most hardware problems? Video Users have the most difficulty with which system? Peripherals

8 of 10 Using Tables What percent of hardware problems relate to the drives and RAM? 18.5 % What would you do to decrease initial problems? Send better instructions about the peripherals

9 of 10 Using Tables How were the first two questions different from the last two? The first two questions could be answered by reading directly from the table. The last two questions required you to make some calculations and judgments about the data in the table. There is a lot more information in a table than what is written directly. The information in a table can be interpreted in many ways to draw conclusions and make predictions.

10 of 10 Using Tables Home Construct a table that can be used to compare the features of various models of lawnmowers. The table should have a title and column and row headings. You don’t need to put in the data. When you are done click to see an example.

1 of 12 Using Circle Graphs Home While tables are used for organizing information, graphs are used to present information visually. Different graphs are designed to present different types of information. Circle graphs are best used to show how a whole is divided into its parts.

2 of 12 Using Circle Graphs Circle graphs consist of wedge-shaped segments that together make a whole circle. Each segment should have a name and a value. The graph itself should have a title to describe its purpose. Identify the parts of the graph on the following slide.

3 of 12 Using Circle Graphs Title Segment Segment Name Segment Value

4 of 12 Using Circle Graphs Circle graphs are used to show how a whole is broken up into its parts. In this case, the whole is the total number of students asked about their lunch preference. The parts represent the 4 possible responses.

5 of 12 Using Circle Graphs There are a few things you should notice about circle graphs. The segments must add up to the total. 17% for hot dogs 20% for sandwiches 23% for hamburgers + 40% for pizza 100% total

6 of 12 Using Circle Graphs There are a few things you should notice about circle graphs. The segment size must be relative to its value. 20% (1/5) of students chose sandwiches so that segment is 1/5 of the circle.

Using Circle Graphs Use the graph to answer the following questions. 7 of 12 Using Circle Graphs Use the graph to answer the following questions. See if you notice a difference between the first two questions, the next two questions, and the last question.

Using Circle Graphs What percent prefer pizza or hamburgers? 8 of 12 Using Circle Graphs What percent prefer pizza or hamburgers? 63% What is the least popular menu item? Hot Dogs

9 of 12 Using Circle Graphs If 500 students were surveyed, how many preferred hamburgers? 115 How many students preferred sandwiches? 100

10 of 12 Using Circle Graphs Half the students (500 total) eat the school lunch every day. The other half will eat only when their favorite food is served. How many students can you expect to serve on pizza day? 350 ( 250 + ( 250 x 40% )) = 350

11 of 12 Using Circle Graphs How were the first two questions different from the next two? How was the last question different? The first two questions could be answered by reading directly from the table. The next two questions required you to make some calculations and judgments about the data in the table. The answer to the last question was a prediction based on the circle graph. The information in a graph can be used in many ways to draw conclusions and make predictions.

12 of 12 Using Circle Graphs Home Construct a circle graph to show the following data about bald eagle populations in 1998 When you are done click to see an example.

1 of 14 Using Bar Graphs Home While tables are used for organizing information, graphs are used to present information visually. Different graphs are designed to present different types of information. Bar graphs are best used to show how a number of objects or events compare in relationship to single property.

2 of 14 Using Bar Graphs Bar graphs consist of a horizontal and vertical scale. One scale identifies the objects to be compared the other scale is numerical. The bar graph gets its name from the lines that identify the measured value of each object. Identify the parts of the graph on the following slide.

Using Bar Graphs 3 of 14 Title Numerical Scale Label Bar Object Scale

4 of 14 Using Bar Graphs Bar graphs are used to compare measurements taken from a number of objects or categories. In this case, the measurement is BTU’s of energy consumption. The categories are the different fuel types.

5 of 14 Using Bar Graphs There are a some important features of bar graphs. First, the numerical scale must be consistent Each division on the vertical scale is one unit. On this graph 1 unit = 1 quadrillion BTU’s Each division must represent the same amount of change from the start to the finish. 1 Quadrillion 1 Quadrillion 1 Quadrillion

6 of 14 Using Bar Graphs The numerical scale must be consistent but there is no limit on the value you place on each division. Our graph was redrawn with a different scale. Now 1 unit = 2 quadrillion BTU’s The scale is still consistent and the data is still the same but the graph looks different.

7 of 14 Using Bar Graphs When each unit represents a larger value there appears to be less difference between the groups. A graph can be misleading or difficult to read depending on the scale you choose.

Using Bar Graphs Use the graph to answer the following questions. 8 of 14 Using Bar Graphs Use the graph to answer the following questions.

Using Bar Graphs How much total energy was used by households in 1997? 9 of 14 Using Bar Graphs How much total energy was used by households in 1997? 10.25 quadrillion BTU’s

10 of 14 Using Bar Graphs How many times as much natural gas is used compared to LP gas? Over 14 times as much

11 of 14 Using Bar Graphs In this graph, a second bar was added for each category with data from 1979. This bar graph can then be used to compare the data from 2 different years.

12 of 14 Using Bar Graphs What is the percent increase in total energy usage from 1979 to 1997? About 5% What is the percent increase in electricity usage from 1979 to 1997. About 46%

13 of 14 Using Bar Graphs From 79 to 97 the US population increased by 17%, electricity consumption increased 46%, yet household energy consumption increased only 5%. How can you account for this? The big increase in electricity use is probably related to the huge increase in electronic devices. The relatively small increase in total consumption is probably related to savings from more energy efficient devices.

14 of 14 Using Bar Graphs Home Construct a bar graph to show the following data about US Endangered Animal Species When you are done click to see an example.

1 of 14 Using Line Graphs Home While tables are used for organizing information, graphs are used to present information visually. Different graphs are designed to present different types of information. Line graphs are best used to show a relationship between two measured quantities.

2 of 14 Using Line Graphs Line graphs consist of a horizontal and vertical scale but both scales are numerical since each represents a measured quantity. Line graphs are drawn by connecting observed points where the two numerical quantities intersect. Identify the parts of the graph on the following slide.

Using Line Graphs 3 of 14 Title Observed Points Numerical Scale Label

4 of 14 Using Line Graphs Line graphs are used to compare two measured quantities. In this case, the two quantities being compared are time and number of cell phone subscribers. The dots represent the points at which actual measurements were made.

5 of 14 Using Line Graphs The points are located on the graph at the intersection of two measured quantities. In 1994, there were 24.134 million cell phone subscribers. In 1996, there were 44.042 million. Once the points are established a line is drawn to fit the data as well as possible.

7 of 14 Using Line Graphs The number of cell phone subscribers was actually counted in 1984, 1986, 1988, etc. But what was the count before 1984 or after 1998 or in 1995? A line graph can be used to make predictions when no actual measurements were made.

6 of 14 Using Line Graphs To determine the number of cell phone subscribers in 1995, go up from 1995 to the line and over to vertical scale. According to the line graph there were about 33 million cell phone subscribers in 1995. The line graph let us predict a value that we didn’t actually measure.

7 of 14 Using Line Graphs To predict the number of cell phone subscribers in 1999, you must extend the line then go up from 1999 and over to the vertical scale. According to the line graph there may be about 85 million cell phone subscribers in 1999. How is the 1999 prediction different from the 1995 prediction?

8 of 14 Using Line Graphs The 1995 prediction occurred between 2 measured points. The 1999 prediction occurred after the last actual measurement. In which prediction do you have the most confidence?

9 of 14 Using Line Graphs The 1995 prediction is more reliable because we know what happened before and after. However, we don’t know what happened after 1998. After 1998, cell phone subscriptions may continue to increase which is what we assumed. ? They may level off. They may decline. We can’t be sure what will happen after 1998.

Using Line Graphs How many cell phone subscribers were there in 1991? 10 of 14 Using Line Graphs How many cell phone subscribers were there in 1991? About 8 million In what year did the number of subscribers hit 55 million? In 1997

11 of 14 Using Line Graphs Construct a line graph to show the following data about the percent of US high school dropouts 1975 13.9 1980 14.1 1985 12.6 1990 12.1 1995 10.5 When you are done click to see an example.

Using Line Graphs Match the type of graph with its use. Circle Graph Home Match the type of graph with its use. Used to compare several categories Shows the relationship between two measured quantities Shows a single measurement of a number objects or events Shows how a whole is divided into its parts. Used to make predictions and show trends Circle Graph Bar Graph Line Graph

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