Level 1: Correlation- When asked to summarize the figure, the students were first able to identify a reverse-correlation between survival and level of treatment (X-ray or Bleomycin). This first level discussion allowed the students to gain confidence in their own interpretation while also emphasizing the key point of the experiment.
Level 2: Comparison- Once the basic correlation was established, the students began to consider the differences between cells treated with the APE1 suppressor compared to the other suppressor and the control. Comparisons were also made between the two treatment conditions and the two cell types used and the differences noted. This provided an opportunity to discuss why the authors repeated the experiments under different conditions with different cell types.
Level 3: Significance- While this class did not discuss statistical significance at this point, students were asked to determine their confidence in the data presented. This discussion was initiated to introduce the controls performed (untreated vs. treatment with an unrelated suppressor, for example) and the importance of these controls in interpreting the data.
Level 4: Relevance- Once the data had been analyzed, it was then possible to discuss the significance of the experimental results with respect to DNA repair and to connect these experimental results with the information the students had learned previously.
By breaking down the figure from less complex to more complex, the students were given an opportunity to slowly bring complicated data into focus, gain a better appreciation for how a good experiment is designed and connect current research with core concepts.
Quinn Vega (email@example.com) is a professor in the department of biology and molecular biology at Montclair State University.