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 2 – Pepper Plant Growth Experiment

Continuing to encourage students to think about the experiment, this item asks students to identify the best measure of a fertilizer’s effectiveness to grow more peppers and to explain their answers based on their knowledge of plant life cycles. Students obtained full credit (2 points) if they selected “number of flowers” and explained that flowers are necessary to produce peppers. Students obtained partial credit (1 point) if they selected “number of flowers” correctly but failed to provide a correct explanation.

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Maximum Score Points: 2
Content Domain: Biology
Topic Area: Life Cycles, Reproduction, and Heredity
Cognitive Domain: Applying


Exhibit 41 shows that 18 percent of students on average across countries received full credit by identifying “number of flowers” as the best indicator of number of peppers and providing a correct accompanying explanation. Another 18 percent of students earned partial credit by selecting “number of flowers” without providing a correct explanation. Singapore and Lithuania had the highest average performance with 45 and 31 percent of students earning full credit, respectively. Essentially no overall difference was found between the performance of boys and girls.