Source: Earth PD http://bit.ly/1ESoBKp Bar Chart CC http://bit.ly/1zJr3Or Histograph CC http://bit.ly/1Cw91GA Line Chart CC http://bit.ly/1wI3dYU Scatter Plot CC http://bit.ly/1wI3mLQ Pictogram CC http://bit.ly/1AIKtDh Kyoto Map PD http://bit.ly/1JzMMmI
Hi, I'm Jensen Morgan. We're going to talk about some great concepts in environmental science. Today's topic is graphic literacy. So let's get started. We're going to talk about graphic literacy, the various parts of a graph, and different types of graphs and visuals that can be used.
Graphic literacy is important to understanding scientific text, as well as comprehending the ideas behind graphical representations of information. Information in science is often represented visually because it can be highly impactful and efficient to communicate. It can save time because the viewer can grasp concepts more quickly, and it can show trends and distribution, making prediction easier.
Graphic literacy becomes very important when information has been presented in a biased manner. Being able to spot this helps the viewer take bias into account when trying to see science objectively. Let's look at an example.
This graph here shows greenhouse gas emissions of a fictional company over time. Someone looking at this might interpret that the company's greenhouse gas emissions are decreasing over time. However, if you notice the time span sections at the bottom, they are not presenting regular intervals.
The first section takes place over six years, and the second is also six years. However, the third section is only three years, and the last only two. If you actually kept the intervals from 1990 to 2006 at regular intervals, there would only be three sections.
The new third section from 2002 to 2006 would actual only be five years, and we have 10,000 tons of greenhouse gas emissions. This means the corporation's emissions weren't actually decreasing at all.
Let's break down the anatomy of what most graphs contained for better understanding of what you might encounter. The title is usually at the top or bottom, and indicates what the graph is displaying. The legend can be in various locations, but is right here on this graph. It identifies the meaning of various colors or symbols used in the graph.
The x-axis is always the horizontal axis, and displays a range of values or categories. The y-axis is always the vertical axis, and displays a range of values. Scale is the total range of values on the x or y-axis.
Units are the form of measurement of the values on the x and/or y-axis. In this one it is in tons of greenhouse gas emissions, but it can be number of people, years, et cetera. Axis labels are description of what the values on the axis represent.
This graph doesn't have one, but sometimes footnotes are placed at the bottom of a graph to provide additional explanation or interpretation of the graph. And finally, data is the information that the graph as a whole is displaying.
Let's discuss some different types of graphs that are used in environmental science, for there are many. First step, bar graph-- this is used for showing differences in quantifiable characteristics across groups. It's common characteristics are an x and y-axis, and data depicted using a vertical or horizontal bar.
Histograms are used to show the frequency of various characteristics across groups. Like bar graphs, they commonly have an x and y-axis with data depicted using a vertical or horizontal bar. Line graphs are used to show a trend in a characteristic relative to changes in time, space, concentration, or whatever. They commonly have an x and y-axis with data depicted as a line connecting data points.
Scatterplots are used to show the relationship between two different characteristics. They commonly have an x and y-axis with data depicted using individual dots for each data point. Pie charts are useful for showing relative proportions of multiple characteristics or groups within a larger group. They commonly have no axes, but are shown as a circle with labeled subdivisions.
Pictographs are like a bar graph or histogram commonly using images for values, or may use the relative size of an image represent various values for comparison purposes. Flow diagrams are used to show process, sequence, or flow, and maybe multi-directional or web-like. They commonly have no axes, but use arrows to show direction of the process connecting images, or text to represent each step.
And finally, maps are used to depict differences in some characteristics, or show the location of various phenomena. They commonly are a map of a region with icons, lines and arrows, and/or coloration.
Now let's have a recap. We talked about graphic literacy, the common anatomy of graphs, and the various types one might encounter environmental science. Well, that's all for today. I hope these concepts have been helpful, and I look forward to next time. Bye.