Displaying Data: Graphing “A Picture is Worth a 1,000 Words”

Components of a Graph Figure Number (e.g., Figure 2.1) Title Label Axes (include units) Graph should be large enough to read and data should fill the graph space Data Source Author(s) Name, Date Published Neatness counts! Learn to use Microsoft Excel Choose appropriate type of graph

Don’t Waste Space!

Components of a Graph Figure Number (e.g., Figure 2.1) Title Label Axes (include units) Graph should be large enough to read and data should fill the graph space Data Source Author(s) Name, Date Published Neatness counts! Learn to use Microsoft Excel Choose appropriate type of graph

Scatter Plot

Line Graph

Column/Bar Graph

Pie Graph

Choose Graph Type Carefully

Statistics Calculating Averages and Standard Deviations

Average & Standard Deviation Average: The value obtained by dividing the sum of a set of quantities by the number of quantities in the set. (Also the “mean value”.) Standard Deviation: The standard deviation is a measure of how spread out your data are. See worksheet on how to calculate Standard Deviation. Median: The number dividing the higher half of a sample from the lower half.

Calculating Standard Deviation for Temperature a)Find the average air temperature. b)Find the difference between the air temp for each sample and the average – let ’ s call this X. For example, if sample 1 was 11.2°C and the average air temperature was 12.0°C, then X 1 = = -0.8°C. c)Square X. So in our example X 1 2 = (-0.8) 2 = 0.64°C 2 d)Repeat the above step for all samples. e)Add up the X 2 values for all samples. f)Divide the value obtained in (e) by the total number of samples minus 1 (n-1). If there were 14 sample then (n- 1) = 13. g)Take the square root of the answer you obtained in step (f). This number value is the standard deviation.

Interpretation Average ± 1 Standard Deviation --> 68% of the data Average ± 2 Standard Deviations --> 95% of the data Average ± 3 Standard Deviations --> Almost all of the data

Calculate Average and Standard Deviation for Moisture and Organic Content (and include in table of data)

Soils Lab What is due

Lab Reports a)Title b)Abstract c)Introduction d)Background Information e)Methods f)Results g)Discussion (Conclusion) h)References i)Appendix

Introduction (One per group - typed) a)A one page introduction to the lab report (One per group - typed) b)A map of the study region with ALL the sample sites marked. (One per group)

Results (One per group - typed) 1.A one paragraph description for each the soils you analyzed. These descriptions should reference the table and graphs below. Be sure to describe the soil, as well as the area from which it was collected. 2.A table summarizing all of the soil data collected by your study (4-6 samples). Be sure to include a summary of all of the data collected (soil color, soil texture, moisture content, organic content, pH, nitrogen, phosphorous, potassium, and lead, etc.). 3.Bar graph of soil moisture data and organic content from all samples analyses by your study (4-6 samples). Be sure to include all the components of a graph and put all the data on the same graph. (One per group) 4.Pie charts for the distribution of grain sizes (sand, silt, clay) for the samples used in your study (4-6 samples)..

Conclusions (One per group - typed) Write a 2 page discussion of the class study. Remember that you have already described your results in the data section above. For this part of the report, you want to describe what your data means, and how your samples compare to others analyzed by other groups. Be sure to think about the questions on the lab handout.

Appendix (One per group) 1.A list (handwritten is OK) of what each team member contributed to the lab. 2.All Raw Data sheets (Tables of data in this lab)