In an article describing hypothesis testing with small sample sizes, Collins and Morris (2008) provided the following description for a z test: "Z is considered significant if the difference is more than roughly two standard deviations above or below zero (or more precisely, |Z| > 1.96)" (p. 464). Based on this description,
(a) Are the authors referring to critical values for a one-tailed z test or a twotailed z test?
(b) What alpha level are the authors referring to?