Table 1 Summary of literature on item context and student response to open-ended natural selection items

Nehm and Ha (2011)

Scale of change: within or between species changes

Trait gain or loss

Trait gain, as well as within species explanations, had more core ideas than items that asked about trait loss and between species items

Nettle (2010)

Human vs. non-human animal

Process of evolution of a single trait within a population

Human examples elicited more correct ideas about variation. Fewer misunderstandings with human example

Opfer et al. (2012)

Animal vs. plant and familiarity of organism

Evolution of a trait

Respondents used more key concepts to explain evolution for familiar and animal contexts than for unfamiliar and plant items. There was no difference in number of cognitive biases demonstrated with either contrast

White and Yamamoto (2011)

Taxonomic distance

Common ancestry

Negative correlation between taxonomic distance and naive ideas