An article in Science (Mann, 11 November 1994) describes two approaches used to try to determine how well programs to improve public schools have worked. The first approach was taken by an economist named Eric Hanushek. Here is part of the description:
Hanushek reviewed 38 studies and found the “startlingly consistent” result that “there is no strong or systematic relationship between school expenditures and student performance.” . .
. Hanushek’s review used a technique called “vote-counting” (p. 961).
The other approach was a meta-analysis and the results are reported as follows:
[The researchers] found systematic positive effects. . . . Indeed, decreased class size, increased teacher experience, increased teacher salaries, and increased per- pupil spending were all positively related to academic performance (p. 962).
Explain why the two approaches yielded different answers and which one you think is more credible.