Scientists construct and interpret figures regularly, but this is a skill that is often difficult for students to master. TIEE puts great emphasis on making and analyzing figures because this ability is so central to the process of scientific inquiry.

Because faculty interpret figures and other visual representations so readily, it is hard for us to appreciate why students might struggle with this task. Below is a list of ideas explaining why students interpret figures with difficulty and how you can help them in your course. See the references for more detail, including cognitive theory and classroom studies.

General Points

• The importance of context — ability to interpret figures develops from understanding how and why the figure was created. Often there is a bigger picture such as the larger question(s), experimental approach, or school of thought which are “invisible” to students. As a result, students don’t understand why the figure is interesting or how it relates to the topic you are teaching.
• The challenge of abstraction — the figure is an abstract representation of some aspect of “nature” which ecologists and students relate to differently. Students often lack the experience to understand the mechanics of generating the figure from observational or experimental data.
• Active vs. passive learning — in lecture, students usually simply listen to a professor’s explanation of figures. Many studies show that most students learn best by actively engaging with the information (e.g. asking questions, talking and listening to other students, working with data).
• Figures as everyday tools — scientists frequently make and use figures to compare effects of variables or look at trends as they develop and examine hypotheses. In a way, figures are a “language” through which scientists communicate with each other. Students with little experience making figures may well not understand the “language” and therefore have difficulty interpreting figures.

Specific Points

• Students may not understand the experimental question or design that is the basis for the figure.
• Axis labels and other aspects of figures (e.g. what “overstory” or “guild” means) may be unknown or unclear to students. As a result, they may not understand the explanation given in class about a figure and may miss the point of the lesson.
• Misinterpretation or misconceptions about terms – student may “understand” a term incorrectly (e.g. metabolism = breathing).
• Confusion over dependent and independent variables
• Keeping track of multiple variables and their covariants — e.g. species loss across latitude on islands receiving different amounts of annual rainfall. Students have to consider a number of factors simultaneously.
• Time is “lost” — time is part of a calculation and not a axis, as in mg/hr.
• Space is “lost” — as when numbers of animals counted along a transect are represented on relative scales (e.g. “relative importance”).
• Limited experience — professor has done research in deserts but some students have never been to a desert.
• Too much is going on — professor is talking, pointing to a projected figure, and student is trying to think and take notes.
• Imprecise reference to figure — professor’s physical actions (pointing, drawing lines with pointer) are not clear or there is a lag between gesture and verbal explanation. Students must try to interpret unclear gestures as well as the figure or try to remember what the professor said a minute ago.
• Poor figure presentation format — students are expected to make quick sketches of figures on power point slides while also writing their comments.

What You Can Do

• Active learning — as much as possible have your students actively engage in figure construction and interpretation. This can be done in large as well as small classes and classes without labs. There are many examples in TIEE’s Issues section.
• Do not assume student understand the question addressed by the figure — ask them what it is. Take the time for students to explain in their own words the experimental design or overall hypothesis/question. This can be done both verbally and in writing. A quick “minute paper”, which can be done in any size class, at the end of lecture will give you feedback about their understanding of a specific figure. (You don’t have to read them all — a quick look at a sample should give you good feedback).
• Think carefully ahead of time about terms that may be unfamiliar to students or that they may misunderstand. Know students’ common misconceptions in ecology.
• Think about aspects “behind” the figure that are intuitive to you but confusing to students. This includes multiple variables, covariation, and “loss” of time and space in the axes.
• Be aware of students’ lack of experience with habitats, tree or animal types, climates, etc. Try to put your students “there” by describing relevant sensations (temperature, wind, sound) or showing images from the web or your own research or travel.
• Be very precise about where you put your pointer. Point to the exact word you are explaining, not the general area on the figure. For example place your pointer directly on the axis. Try to discuss a word or idea at the same time that you physically refer to the figure and not afterwards.
• Give students time to think and write. In particular, remember to pause after completing a point to allow them to do a bit of thinking before going onto the next point. Create a comfortable rhythm for them.
• If possible, have a good copy of the figure in front of students upon which they can write comments. If you use Power Point slides, you can print out copies of key figures for distribution in class (several slides per page). In large classes, students can print these out ahead of time if you make them available online.
• Summarize the main point/question/hypothesis relating to the figure.
• Read the “Step One - Step Two” essay in TIEE titled “Helping Your Students Interpret Figures and Tables”
• Try to remember what it was like when you were a student and teachers asked you to interpret graphs.

References

• CA Berg and DG Philips. 1994. An investigation of the relationship between logical thinking structures and the ability to construct and interpret line graphs. Journal of Research in Science Teaching 31: 323-344.
• GM Bowen, R Wolff-Michael, and MK McGinn. 1999. Interpretation of graphs by university biology students: towards a social practice view of scientific representation practices. Journal of Research in Science Teaching 36: 1020-1043
• GM Bowen and R Wolff-Michael. 1998. Lecturing graphing: what features of lectures contribute to student difficulties in learning to interpret graphs? Research in Science Education 28: 77-90
• J Clement. 1989. The concept of variation and misconceptions in Cartesian graphing. Focus on Learning Problems in Mathematics 11: 77-87
• JH Mathewson. 1999. Visual-spatial thinking: an aspect of science overlooked by educators. Science Education 83: 33-54
• W Schnotz, E Picard, and A Hron. 1993. How do successful and unsuccessful learners use texts and graphics? Learning and Instruction 3: 181-199