Predicting and extending experiments — ACT practice questions

ACT Science might ask for the likely result of a new trial at a condition not tested, the outcome if one material were swapped for another, or which additional experiment would answer a new question. Predictions must follow from the data and the model described, not from outside knowledge alone.

Extending a design means changing only the variable of interest while keeping everything else the same. Wrong choices often change two things at once, or predict a reversal that the passage gives no reason to expect.