The information so obtained has，qualitatively，the same advantages and shortcomings as other kinds of information. Whether to use tests，other kinds of information，or both in a particular situation depends，therefore，upon the evidence from experience concerning comparative validity and upon such factors as cost and availability.这样得到的信息，从性质上讲，与其它种类的信息一样具有优点或缺点。因此，在某一特定情况下，究竟是采用测试还是其他种类的信息，或是两者兼用，取决于有关相对效度的经验方面的证据，也取决于诸如费用和有无来源等因素。
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【今日长难句】
In general，the tests work most effectively when the qualities to be measured can be most precisely defined and least effectively when what is to be measured or predicted can not be well defined.
【句子分析】
句子主干：the tests work most effectively when … and least effectively when …修饰成分：1. in general 为介词短语充当状语，修饰整句话。2. when the qualities can be most precisely defined 和when what is to be measured or predicted can not be well defined 均为时间状语从句，分别修饰work most effectively 和 （work）least effectively3. to be measured 修饰the qualities, 译为：所要测定的特征4. what is to be measured or predicated 为when 引导的时间状语从句内所嵌套的主语从句，译为：索要测量或预测的东西
【基础必备词】
In general 一般而言effectively adv. 有效地，生效地；有力地quality n. 质量，[统计] 品质；特性；measure vt. 测量；估量；权衡precisely adv. 精确地；恰恰define vt. 定义；使明确；规定predict vt. 预报，预言；预知
【参考译文】
In general，the tests work most effectively when the qualities to be measured can be most precisely defined and least effectively when what is to be measured or predicted can not be well defined.一般来说，当所要测定的特征能很精确界定时，测试最为有效;而当所要测定或预测的东西不能明确地界定时，测试的效果则最差。
【明日预告】
Properly used，these tests provide a rapid means of getting comparable information about many people. Sometimes these tests identify students whose high potential has not been previously recognized，but there are many things they do not do.
