Measuring student knowledge and skills

Selected scientific processes
1.
Recognising scientifically investigable questions.
2.
Identifying evidence needed in a scientific investigation.
3.
Drawing or evaluating conclusions.
4.
Communicating valid conclusions.
5.
Demonstrating understanding of scientific concepts.
Figure 14.
Selected scientific processes
1.
Recognising scientifically investigable questions.
2.
Identifying evidence needed in a scientific investigation.
3.
Drawing or evaluating conclusions.
4.
Communicating valid conclusions.
5.
Demonstrating understanding of scientific concepts.

---

Scientific Literacy
63
OECD 1999
Communicating valid conclusions
Communicating to a specified audience valid conclusions from available evidence and data involves
the production of an argument based on the situation and data given, or on relevant additional informa-
tion, expressed in a manner that is appropriate and clear to the given audience.
Demonstrating understanding of scientific concepts
Demonstrating understanding of scientific concepts by applying appropriate concepts in a given sit-
uation involves explaining relationships and possible causes of given changes, or making predictions as
to the effect of given changes, or identifying the factors that influence a given outcome, using scientific
ideas and/or information which have not been given.
Some scientific knowledge is needed for all five processes. In the case of the first four, however, the
knowledge is not intended to be the main “hurdle”, since the aim is to assess the mental processes
involved in gathering, evaluating and communicating valid scientific evidence. In the fifth process, on the
other hand, it is the understanding of the scientific concept involved that is being assessed and this
understanding is the main hurdle.
It is important to point out that, for each of the processes listed above, there is a wide range of task
difficulties, depending upon the scientific concepts and situations involved. The OECD/PISA assess-
ments will ensure that, through country feedback and the field trial, the items selected for the main study
will be at the appropriate level of difficulty for 15-year-olds.