Revealing undergraduate biology students’ conception of variability and error bars within graphing
Fig 6
Frequency of codes used from student explanation of data error bars represent across the categories (a), combinations of categories (b), and specific codes within the categories (c, d, e, f) based on the graph a student created within the GraphSmarts Assessment.
A chi-square test was performed and a single asterisk represents a frequency that was significantly lower than expected. Double asterisk represents a frequency that was significantly higher than expected. Letters above bars represent significant differences from post hoc Dunn test after a significant Kruskal Wallis test. Bar (raw) is a bar graph created with raw data; N = 1071. Bar (ymean) is a bar graph with just means; N = 484. Bar (ymean + errorbars) is a bar graph with means and error bars; N = 391. Catscatter (raw) is a graph similar to graph 3; N = 205. Catscatter (ymean) is a graph with a dot representing the mean for each group; N = 73. Quantscatter is a traditional scatterplot with two numerical variables; N = 184.