Before children are set eleven plus tests the questions are tested on a restricted number of children. The results of the preliminary testing, however, are meant to apply to many children. Suppose someone, in their wisdom, wanted to test aspects of the ability of all the children writing relevant eleven plus examinations - for example, every child sitting verbal reasoning tests.
The examiners would need to find questions that were covered in all the regions – because there are variations in types of verbal reasoning questions from county to county. There must be, however, a set of core questions that any child would expect to meet. Testing is usually restricted to a small sample which is chosen to be as representative as possible of all the children concerned.
It is vitally important that a sample is free from bias. The questions have to be able to suit children living in inner city conditions as well as those from the leafy suburbs. The questions would be biased, for example, if only children of families owning a computer were sampled.
Would a question of this nature be bias free?
If no prickly animals can move fast, and no animals that can only move slowly can climb trees, which of the following statements are correct?
All animals that can only move slowly are prickly
Prickly animals can sometimes move slowly
All animals that can move quickly can climb trees
No prickly animals can climb trees