The book also mentions the problems of confounding. Subjective and objective measures are defined. Sampling is approached through the idea of trying to get a representative sample. Random samples are said to be good - but they are assumed to be representative. Going into the street and talking to who is there is also an opportunity sample, but is not really a group that already exists in the same well-defined sense.
Measurement introduces the standard nominal, ordinal, interval and ratio scales.
One of the test questions would only accept 'random' as the answer to what sort of sample is every 1000th name on the Electoral register. Systematic samples are not mentioned. There is some loose use of language. The median is defined as 'a score that is bigger than half the scores'. But consider the set of data 1,2,3,4,4,4,5,6,8.