So far we have made observations, asked questions, formed hypotheses and created experiments. This brings us to collecting and presenting data. Data can be either qualitative or quantitative in nature. Observations can be considered qualitative data. Numerical data is quantitative data. Quantitative data requires measuring tools, a measurement system and conventions for reporting numbers with precision. Discussion on these topics really do require additional blog posts.

For now, I will focus on presenting data. When scientists collect data, we are then tasked with finding patterns in that data and drawing conclusions. One way in which we can discover patterns in the data is by graphing. You may have learned of different graphing methods in your math class. We have bar graphs, pie charts, and Cartesian plane (X- and Y-axis) graphing. Depending on your data and what you want to present to your audience, some graphical presentations will be better than others. Experience using all the different graphing methods is important for eventually choosing the best option for your data.

When we graph data using a Cartesian plane, we are usually working in Quadrant I, with positive numerical data. Defining the field, we have the X-axis on the horizontal axis and the Y-axis on the vertical. The independent variable is usually plotted on the X-axis. The independent variable is also known as the manipulated variable. This the variable that we choose in our experimental design. The data we collect is usually graphed on the Y-axis. That is our responding variable. This variable is also called the dependent variable.

See the image below for a graph to data I collected in an experiment to determine how sunlight affects bean germination. On the X-axis, or the independent variable, you will see the experimental variable of whether my beans were exposed to light. On the Y-axis, the dependent variable, I place the data (the measurements) that I collected from the experiment. I chose a bar graph and averaged the data from multiple beans I had germinating in each group. What pattern can you see from the data presentation?