This Test Guideline lists methods for determining the density of liquids and solids, giving only a very succinct description of them. The density of a substance is the quotient of its mass and its volume and is expressed in kg/m3. Several methods are for liquid substance only: hydrometer,...

This Test Guideline describes methods to measure the viscosity of liquids. The methods listed are appropriate in principle for the investigation of Newtonian liquids. The measurement of non-Newtonian liquids is only possible with the rotational viscometer. Viscosity measurements are carried out...

While most 15-year-old students spend part of their after-school time doing homework, the amount of time they spend on it shrank between 2003 and 2012. Socio-economically advantaged students and students who attend socio-economically advantaged schools tend to spend more time doing homework....

This Test Guideline lists methods for determining the density of liquids and solids, giving only a succinct description of them. The density of a substance is the quotient of its mass and its volume and is expressed in SI units as kg/m3 at a specified temperature. Several methods are for liquid...

This Test Guideline describes methods to measure the viscosity of liquids. Most of the methods listed are appropriate for the investigation of Newtonian liquids. The measurement of non-Newtonian liquids is possible with the rotational viscometer. Viscosity measurements are carried out according...

This Test Guideline describes the procedure for the electronic determination of pH of an undiluted aqueous solution or dispersion, the pH of a dilution of a solution or dispersion in water, or the pH of a chemical diluted to end-use concentration. It also describes procedures to determine acid...

Fewer 15-year-olds in East Asian countries reported that they use memorisation than did 15‑year‑olds in some of the English-speaking countries to whom they are often compared. In no PISA-participating education system did boys report more intensive use of memorisation than girls when...

Some 65% of socio-economically advantaged students reported that they know well or have often heard of the concept of quadratic function, on average across OECD countries; but only 43% of disadvantaged students so reported. On average across OECD countries, the 20% of students who are most...

In most school systems, over 50% of 15-year-olds students attend schools that compete with another school to attract students from the same residential area. Across countries and economies, performance is unrelated to whether or not schools have to compete for students. When choosing a school...