**3.4 Step 4: Testing and collecting students' unscientific understanding**

The revised MCQ-FR is then used to collect preliminary data, which are students' unscientific understanding or illogical reasons. For example, in answering the question in **Figure 7**, some students believed that *option D would be the highest rate because the concentration of two reactants (H*2 *and I*2*) is the same*. These illogical reasons are then collected and employed as the basis to develop the prototype multi-tier instrument.
