Exploring the effect of task instructions on topic beliefs and topic belief justifications: A mixed methods study

•Experimental data showed that task instructions affect topic beliefs and topic belief justifications.•Some participants’ beliefs became weaker after they read, whereas others became or stronger.•Interview data revealed two distinct reader profiles: belief-reflection and belief-protection.•The quantitative data showed differences in beliefs; the qualitative data explained why. The purpose of this mixed methods study was to investigate whether task instructions that asked adolescents to evaluate the merit of both sides of a controversial issue would affect their topic beliefs and topic belief justifications after they read belief-consistent and belief-inconsistent information. In the quantitative phase, we conducted an experiment in which high school students (n=45) were randomly assigned to one of four conditions and received their respective pre-reading task instructions. Quantitative analyses showed that task instructions affected topic beliefs and belief justifications. However, inspection of topic belief scores within each condition indicated that some individuals’ beliefs became weaker, whereas others’ became stronger. In the qualitative phase, we conducted interviews to explain why this occurred. The interview data revealed two distinct reader profiles: belief-reflection and belief-protection. The data sets were complementary: the quantitative data indicated group differences in topic beliefs and belief justifications, and the qualitative data allowed us to explain differences within and across groups.