A town in Italy, but it also stands for Programme for International Student Assessment.

I’m not going to comment on the original “Pisa Shock” (after the results for the first study were released) or the state of the German educational system. I’m not even going to comment on the results of the recent study. (Key facts are here, the “executive summary” (56 pages) is here.)

I just want to give you a short list of questions that 15-year olds were asked for the recent study. Each question is preceded by an introductory text.

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Text 1:

Acid Rain
Below is a photo of statues called Caryatids that were built on the Acropolis in Athens more than 2500 years ago. The statues are made of a type of rock called marble. Marble is composed of calcium carbonate. In 1980, the original statues were transferred inside the museum of the Acropolis and were replaced by replicas. The original statues were being eaten away by acid rain. The effect of acid rain on marble can be modelled by placing chips of marble in vinegar overnight. Vinegar and acid rain have about the same acidity level. When a marble chip is placed in vinegar, bubbles of gas form. The mass of the dry marble chip can be found before and after the experiment.

Question 1:

“A marble chip has a mass of 2.0 grams before being immersed in vinegar overnight. The chip is removed and dried the next day. What will the mass of the dried marble chip be?”
A. Less than 2.0 grams
B. Exactly 2.0 grams
C. Between 2.0 and 2.4 grams
D. More than 2.4 grams
Competency: Using scientific evidence, Knowledge category: “Physical systems”, Difficulty: 460 [easy], Percentage of correct answers (OECD countries): 66.7%

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Text 2:

Clothes
A team of British scientists is developing “intelligent” clothes that will give disabled children the power of “speech”. Children wearing waistcoats made of a unique electrotextile, linked to a speech synthesiser, will be able to make themselves understood simply by tapping on the touchsensitive material. The material is made up of normal cloth and an ingenious mesh of carbon-impregnated fibres that can conduct electricity. When pressure is applied to the fabric, the pattern of signals that passes through the conducting fibres is altered and a computer chip can work out where the cloth has been touched. It then can trigger whatever electronic device is attached to it, which could be no bigger than two boxes of matches. “The smart bit is in how we weave the fabric and how we send signals through it – and we can weave it into existing fabric designs so you cannot see it’s in there,” says one of the scientists. Without being damaged, the material can be washed, wrapped around objects or scrunched up. The scientist also claims it can be mass-produced cheaply.

Question 2:

Can these claims made in the article be tested through scientific investigation in the laboratory?
Circle either “Yes” or “No” for each.
The material can be washed without being damaged.
The material can be wrapped around objects without being damaged.
The material can be scrunched up without being damaged.
The material can be mass-produced cheaply.

Competency: Identifying scientific issues, Knowledge category: “Scientific enquiry”, Difficulty: 567 , percentage of correct answers (OECD countries): 47.9%

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Text 3:

Greenhouse
The grenhouse efect: fact or fiction?
Living things need energy to survive. The energy that sustains life on the Earth comes from the Sun, which radiates energy into space because it is so hot. A tiny proportion of this energy reaches the Earth. The Earth’s atmosphere acts like a protective blanket over the surface of our planet, preventing the variations in temperature that would exist in an airless world. Most of the radiated energy coming from the Sun passes through the Earth’s atmosphere. The Earth absorbs some of this energy, and some is reflected back from the Earth’s surface. Part of this reflected energy is absorbed by the atmosphere. As a result of this the average temperature above the Earth’s surface is higher than it would be if there were no atmosphere. The Earth’s atmosphere has the same effect as a greenhouse, hence the term greenhouse effect. The greenhouse effect is said to have become more pronounced during the twentieth century. It is a fact that the average temperature of the Earth’s atmosphere has increased. In newspapers and periodicals the increased carbon dioxide emission is often stated as the main source of the temperature rise in the twentieth century. A student named André becomes interested in the possible relationship between the average temperature of the Earth’s atmosphere and the carbon dioxide emission on the Earth. In a library he comes across the following two graphs.

[Two plots, both with the time from 1860 to 1990 on the x axis.]

y-axis Plot 1: Carbon dioxide emission thousand millions of tonnes per year. Seems to be exponentially increasing just until about 1980 or so, when it flattens.

y-axis Plot 2: Average temperature of the Earth’s atmosphere (°c) . Slightly zig-zaggy, but still clearly rising by 1°C in the given period.

André concludes from these two graphs that it is certain that the increase in the average temperature of the Earth’s atmosphere is due to the increase in the carbon dioxide emission.

Question 3:

André persists in his conclusion that the average temperature rise of the Earth’s atmosphere is caused by the increase in the carbon dioxide emission. But Jeanne thinks that his conclusion is premature. She says: “Before accepting this conclusion you must be sure that other factors that could influence the greenhouse effect are constant”. Name one of the factors that Jeanne means.

Competency: Explaining phenomena scientifically, Knowledge category: “Earth and space systems”, Difficulty: 709 [difficult], Percentage of correct answers (OECD countries): 18.9%

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