Happy Tuesday Scientists! Today: DQ: Which type of graph would be best for graphing your rocket data? Graphing Study Guide and Graphing Rocket Data More Time and Distance Graphs

Graphing Study Guide Are you ready to go? Complete the handout!

There are 4 major types of graphs we’ll use this year. I can remember that

Types of Data Discrete data = consist of categories (days of the week, kind of animal, color) Continuous data = consist of measurements involving a scale with equal measurements; a range of values (temperature, length of time in hours, height in centimeters)

Four major types of graphs Pie chart/graph = consist of categories (display percentages) Bar graph = used to represent discrete data; the IV is typically qualitative and DV is typically quantitative

Four major types of graphing 3. Line graph = used to represent continuous data, usually tracking changes over time; the IV and DV are both quantitative and the line connecting the points has meaning 4. Scatter plot = similar to a line graph, but the data points are NOT connected because a connecting line would have no meaning; a line of best fit might be constructed to show a trend in the data; IV and DV are typically both quantitative

Scatter plot This is a line of best fit – it is a straight line that comes as close to possible as all the data points The data points should NOT be directly connected because the IV is discrete

Bar Graph This is what we mean by discrete data – it’s a category and there’s no “middle value” between each category

Line Graph Each value here has meaning (I could determine Jill’s elevation at 3.2 hours) so I connect my data points with a line

Pie chart Here I have data organized in a percentage out of 100 – this is good way to represent it

A few final thoughts Scientists must represent their data graphically in a fair way that tells the most accurate story It is possible to change the scale of a graph to make it look like the data tells a much different story than the numbers actually show Additional labels might also be used to make the reader infer certain things from the same set of data

For example… At most, how different is the average rainfall from this year’s rainfall? This graph has been manipulated to make it look like there is a much bigger difference in rainfall than 0.4 cm Bad scientist!

A more accurate graph Good scientist!

Scatter Plots Scatter Graphs Scatter Plots Scatter graphs are used to show whether there is a relationship between two sets of data. The relationship between the data can be described as either: Shoe Size Annual Income Height Soup Sales Temperature Scatter Plots Scatter Plots 1. A positive correlation. As one quantity increases so does the other. 2. A negative correlation. As one quantity increases the other decreases. 3. No correlation. Both quantities vary with no clear relationship. Positive Correlation Negative correlation No correlation

Scatter Plots Scatter Graphs Scatter Plots 1. A positive correlation. As one quantity increases so does the other. 2. A negative correlation. As one quantity increases the other decreases. 3. No correlation. Both quantities vary with no clear relationship. Scatter graphs are used to show whether there is a relationship between two sets of data. The relationship between the data can be described as either: Shoe Size Annual Income Height Soup Sales Temperature Scatter Plots A positive correlation is characterised by a straight line with a positive gradient. A negative correlation is characterised by a straight line with a negative gradient.

Petrol consumption (mpg) State the type of correlation for the scatter graphs below and write a sentence describing the relationship in each case. Height KS 3 Results Sales of Sun cream Maths test scores Heating bill (£) Car engine size (cc) Outside air temperature Daily hours of sunshine Physics test scores Daily rainfall totals (mm) Sales of Ice Cream Petrol consumption (mpg) 1 2 3 4 5 6 Scatter Plots Positive Negative None People tend to buy less ice cream in rainier weather. There is no relationship between KS 3 results and the height of students. People tend to buy more sun cream when the weather is sunnier. People with higher maths scores tend to get higher physics scores. As the engine size of cars increase, they use more petrol. (Less mpg) As the outside air temperature increases, heating bills will be lower. Negative Positive Negative

A positive or negative correlation is characterised by a straight line with a positive /negative gradient. The strength of the correlation depends on the spread of points around the imagined line. Strong Positive Moderate Positive Weak Positive Strong negative Moderate Negative Weak negative

Drawing a Line of Best Fit A line of best fit can be drawn to data that shows a correlation. The stronger the correlation between the data, the easier it is to draw the line. The line can be drawn by eye and should have roughly the same number of data points on either side. Lobf The sum of the vertical distances above the line should be roughly the same as those below.

D-TAILS D-TAILS is an acronym used to help you remember everything you need to create a successful graph.

D-TAILS Data covers 50% of the graph area and is accurately placed. NO!!! YES!!!

D-TAILS Title Includes what the graph is about and both the manipulated and responding variables. Hours of Sleep vs. Quiz Scores

D-TAILS Axis Labels – manipulated variable is always on the x-axis and responding variable is always on the y-axis Hours of Sleep vs. Quiz Scores Quiz Scores Sleep

D-TAILS Interval Marks Consistent spacing and always start at zero! Hours of Sleep vs. Quiz Scores 100 75 Quiz Scores 50 25 0 1 2 3 4 5 6 7 8 Sleep

D-TAILS Label Units In ( ) after the axis label, include the proper units (if there are units) Hours of Sleep vs. Quiz Scores 100 75 Quiz Scores (%) 50 25 0 1 2 3 4 5 6 7 8 Sleep (hrs)

D-TAILS Scale Always go by an even scale. Ex: 1,2,3,4 NOT 1,2,4,8 Hours of Sleep vs. Quiz Scores 100 75 Quiz Scores (%) 50 25 0 1 2 3 4 5 6 7 8 Sleep (hrs)

Appropriate type of graph for your data Title with IV and DV Graphing check list Appropriate type of graph for your data Title with IV and DV Labels on each axis Axes have consistent intervals

Graph your rocket data Use the average distance for each rocket You may graph your data using the computer (excel or google sheets) You may graph your data by hand on graph paper