Findings from the TIMSS 2019 Problem Solving and Inquiry Tasks

Ina V.S. Mullis, Michael O. Martin, Bethany Fishbein, Pierre Foy, and Sebastian Moncaleano

Chapter 4: Science Grade 8

Pepper Plants

Screen 12 – Evaluate Data from an Example Experimental Setup

Screen 12 presents the same graph as shown in Screen 11, but this item asks students to describe the effects of Fertilizer A on pepper plant growth compared to the effects of Fertilizer B. Students were awarded full credit (2 points) if their responses included two elements: 1) compared to no fertilizer, Fertilizer A increased the number of flowers in the pepper plants more than Fertilizer B did and 2) Fertilizer B affected the height of the plants while Fertilizer A did not. Students whose responses only included one of these elements received partial credit (1 point).

Click video to play

Maximum Score Points: 2
Content Domain: Biology
Topic Area: Ecosystems
Cognitive Domain: Applying
Science Practice: Working with Data


Exhibit 53 shows 38 percent of students on average across countries having earned full credit by giving two differences between the effects of the fertilizers. Another 16 percent on average earned partial credit by giving one difference. Girls performed better than boys, on average across countries.