1. Presenting Scientific Data  Scientists need a way to organize their data to make it easier to observe patterns or trends. 2 common ways:  Graphs (charts)  Data Tables Must always use same unit of measure within chart or graph or data is meaningless.

2. X and Y axes – Which is Which? Independent Variable (Known) Dependent Variable (Unknown)

3. Line Graph-used to show the change of one piece of information as it relates to another change  Line Graph  shows the relationship between 2 variables  Most useful for showing trends, especially over time

4. Typical Line Graph Trends in Recorded Music Sales- Physical and Digital $Billions$ of Dollars in Sales Year Notice 2 series – can easily compare them to each other.

5. Bar Graph-Used to compare amounts Bar Graph  shows information collected by counting  The higher the bar, the greater the value. Always use Bar Graph when 1 set of data is WORDS.

6. Pie Chart-used to show part of a whole  Pie Graph  Shows distribution of parts within a whole quantity  Data must be converted to percentages.

7. Scatter Plot  Single point measurements  Used to show an overall trend (or lack of a trend) in data  Used to see if one event affects another event

8.  Title-Summarizes info being represented  Independent Variable-Variable that is controlled by experimenter (time, depth, temperature and is placed on the X axis)  Dependent Variable- Variable that is directly affected by the independent variable. The result of what happens as time, depth and temperature changed. This is placed on the Y axis. Parts of a Graph

9.  Scales for each variable-In constructing a graph, you need to know where to plot the points of your data. You must use a scale to do this. You must take up only space needed. It isn’t wise to have a run on scale making the graph hard to manage. Scales should start with 0 and climb in intervals such as multiples of 2, 5, 10, etc. The scale of numbers will be decided by your data.

10. Legend-A description concerning the graph’s data, short and concise.

11. Mean-determined by adding the numbers in a set of data and dividing by the number of values. Median-The middle number in a set of data. (If there is an even set of numbers in the data, take average of the two middle numbers ie., Ex: 2,3,4,8,12,16,20 median 8 Ex: 3,5,8,11,17,19,27,30 median 11 + 17=28/2=14 Mode-the number that occurs most often in a set of data Ex: 3,4,6,6,7,9,9,9,12,12,15 mode = 9 TO DETERMINNE MEDIAN AND MODE THE NUMBERS IN THE SET OF DATA MUST BE PUT IN NUMERICAL ORDER

12.  Extrapolate- extending the graph, along the same slope, above or below measured data.  Interpolate- predicting data between two measured points on the graph

13. Summary  Time to write your recall questions and summary of your notes….