1 Presenting Data
After you have collected data in an experiment, you need to figure out the best way to present that data in a meaningful way. Depending on the type of data, and the story that you are trying to tell using that data, you may present your data in different ways.
Descriptive titles
All figures that present data should stand alone – this means that you should be able to interpret the information contained in the figure without referring to anything else (such as the methods section of the paper). This means that all figures should have a descriptive title that gives information about the independent and dependent variable. Another way to state this is that the title should describe what you are testing and what you are measuring. A good starting point to developing a title is “the effect of [the independent variable] on the [dependent variable].”
Here are some examples of good titles for figures:
- The effect of exercise on heart rate
- Growth rates of E. coli at different temperatures
- The relationship between heat shock time and transformation efficiency
Here are a few less effective titles:
- Heart rate and exercise
- Graph of E. coli temperature growth
- Table for experiment 1
Data Tables
The easiest way to organize data is by putting it into a data table. In most data tables, the independent variable (the variable that you are testing or changing on purpose) will be in the column to the left and the dependent variable(s) will be across the top of the table. You should use a data table while you are collecting your data and to display your data when the actual numerical values of the data are more important than the trends.
Be sure to:
- Label each row and column so that the table can be interpreted
- Include the units that are being used
- Add a descriptive title for the table
Example
You are evaluating the effect of different types of fertilizers on plant growth. You plant 12 tomato plants in pots that are the same size and which contain the same type of soil. You divide the plants into three groups, where each group contains four plants. To the first group, you do not add fertilizer and the plants are watered with plain water. The second and third groups are watered with two different brands of fertilizer. After three weeks, you measure the growth of each plant in centimeters and calculate the average growth for each type of fertilizer.
| Treatment | Plant Height (cm) | ||||
| Plant 1 | Plant 2 | Plant 3 | Plant 4 | Average | |
| No treatment | 10 | 12 | 8 | 9 | 9.75 |
| Brand A | 15 | 16 | 14 | 12 | 14.25 |
| Brand B | 22 | 25 | 21 | 27 | 23.75 |
Scientific Method Review: Can you identify the key parts of the scientific method from this experiment?
Graphing data
Graphs are used to display data because it is easier to see trends in the data when it is displayed visually compared to when it is displayed numerically in a table. Complicated data can often be displayed and interpreted more easily in a graph format than in a data