Experiment!: Planning, Implementing and Interpreting

Further Reading

Biographical books are often a good source of information about how scientists get and develop ideas. Research papers tend to leave these aspects out. Look for biographies of scientists in your field. Crease [8] gives ten short biographies of experiments in physics. Though some of them do not fulfill our criteria for experiments they are well worth reading.

ANSWERS FOR EXERCISES

6.1 See the discussion in the two paragraphs below the exercise.

6.2 To express a causal relationship, a sentence must include both a cause and an effect. Here are some instances from the examples. (6.1) The heart causes the arterial pulse. (6.2) Cold causes the O-ring to loose its resilience. (6.3) Crossing a dominant plant with a recessive (cause) results in a dominant offspring (effect), regardless of if the pollen or egg came from the dominant plant. (6.4) Adsorption of phage to bacteria causes transfer of phage DNA to the interior of the bacteria. (6.5) Applying an electric force, opposed to the force of gravity, to charged oil drops causes them to hover, if it balances the gravitational force. (6.6) A post injection with sufficiently low momentum (cause) enriches the overlean wake of the main injection enough to render it combustible (effect). (6.7) A longer tail ornament in the male widowbird causes greater mating success.

6.3 In examples 6.1–6.2, no precautions are needed because the effects clearly arise from the treatments. (6.3) Mendel's large samples made it easier for ...