Final Answer:
Josiah could test the paper type as a second variable in this situation. By experimenting with different paper types using Caleb's pencil, he can determine if paper characteristics contribute to or mitigate pencil smears.
Step-by-step explanation:
Josiah, experiencing pencil smears with Brand A, hypothesizes that the brand of pencil might be the culprit. To conduct a more comprehensive investigation, he should introduce a second variable – the type of paper.
Different papers possess distinct absorbency levels and textures, which can significantly affect the propensity of pencils to smear. By borrowing Caleb's pencil and using it on various paper types, Josiah can discern whether the paper's characteristics contribute to or mitigate the issue of pencil smears.
This two-variable experiment aligns with the scientific method, allowing Josiah to systematically explore and analyze the factors influencing the observed phenomenon.
It also helps in establishing a more robust conclusion about the primary cause of smearing, providing a clearer understanding of whether the pencil brand alone is responsible or if the paper type plays a significant role.