Stella_Cottrell_Critical_Thinking_Skills_Deve

Authenticity (p. 130)

1Probably authentic, as such documents originated in cathedrals and could have become lost in library stacks over the years.

checks would need to be made to validate the manuscript's age and origins, or provenance.

2Probably not authentic. Such items are rare and usually found in libraries, museums, private collections or religious institutions.

Controlling for variables (p. 140)

Passage 8.4 (p. 136)

The experiment requires a control group to changes in night vision between those

who ate the capsules of carrot extracts and those who didn't. Some variables that would need to be controlled are: diet, which could affect the results; activities which might tire the eyes; previous levels of vision and visual problems; whether participants already had diets high in carrots, allowing no further room for improvement.

3A collection of 1000 autographs by Elvis Presley could be authentic but such a collection would be valuable and it is unlikely that it would be bought without a viewing. It is more likely that an authentic collection would be sold at auction.

4Probably not authentic. It is unlikely, though not impossible, that such an unpublished diary would fall into the possession of a student.

5Probably authentic: such letters are found in collections in major libraries.

6Probably not authentic: such valuable pictures are found occasionally in attics of old houses or behind other paintings, but not usually in modern garages and not in such large numbers.

7Probably authentic: it could be carbon dated to check its age so would be difficult to fake.

8Probably authentic: such items might well be kept at a prison and the governor could have overall responsibility for their care.

Passage 8.5 (p. 136)

The research should take into account such variables as whether participants liked any kind of perfumed soap at all, and whether the scents were equally strong. If not, then participants might have chosen on the basis of the strength of the perfume rather than its scent.

Passage 8.6 (p. 136)

There are many variables that could affect the research outcomes here. The researchers need to check such details as: how closely related the participants were to the bereaved; the frequency and kind of contact and interaction between the people in the sample and the deceased before the bereavement; whether participants attended the funeral; the kinds of work that participants are involved in; for how much time they were usually absent from work before the bereavement; whether they had any illnesses or other conditions likely to make them miss work. Each group would need to have roughly equal numbers of people from each circumstance. However, it could be that a particular combination of these variables has an effect on time off work and it would be hard to control for that in the first set of research.