统计问题（21）：不同资料，应选择何种统计学分析方法？
1.两家航空公司的工作人员因值勤而心脏病发作数的比较
2.开始新饮食前后痛风患者尿酸浓度的变化
3.健康调查中高收入和低收入家庭的人中胆固醇的浓度的差异性
4.汽车颜色与车主个性类型的关联
A.卡方 B.t检验 C. logRank
D.泊松检验 E.pearson相关 F. 配对t检验
Question
Which of the following statistical tests would be your firstchoice in each of the studies below?Test:1 χ2forcontingency tables2 Two samplettest3 Log rank test4 Poisson test5 Pearson’s correlation coefficient6 Pairedttest
Study:a) The occurrence of heart attacks on duty in thestaff of two airlinesb) Change in uric acid concentrations in people withgout before and after starting a new dietc) Cholesterol concentrations in people from high andlow income households in a health surveyd) The association of car colour with owner’spersonality type
Answer
a) Poisson distribution based testb) Pairedttestc) Two samplettestd) χ2testHeart attacks are likely to be a rare occurrence in airlinestaff on duty and to occur in a large pool of susceptible people. The Poissondistribution models this type of study well.
Uric acid can be measured on acontinuous scale and follows a fairly symmetrical distribution. Ifconcentrations are measured in each person before and after starting a diet,then the two measurements are paired within individuals and their differencewill probably follow a normal distribution. The pairedttest fitsthe bill.
Cholesterol concentrations inpeople from households with high and low incomes in a health survey can also bemeasured on a continuous scale. However, the people with a high or a low incomeare different and cannot be paired, so a two samplettest isappropriate. The test works best if the cholesterol concentration is normallydistributed, which is the case in most populations.
Car colour falls into categorieswith no particular value or order and the same is true of personality type. χ2tests may be used to assess associationsbetween categorical variables. This could be done for all colours and allpersonality types in one table to produce a global assessment of “something isgoing on,” or this could be done for one colour and one personality type at atime by splitting the data into two categories, such as “red and not red”“extrovert and not extrovert.”中文解释：
1.心脏病发作在航空公司值班人员中很少发生，大量易感人群中将会发生若干病例。泊松分布很好地模拟了这类研究。
2.尿酸可以连续规模测量，并遵循相当对称的分布。如果在开始饮食之前和之后对每个人进行浓度测量，则两个测量值将在个人内配对，并且它们的差值可能遵循正态分布。配对t检验符合要求。
3.在健康调查中，高收入和低收入家庭的人中的胆固醇浓度也可以连续测量。但是，高收入或低收入的人是不同的，无法配对，因此两样本t检验是合适的。如果胆固醇浓度呈正态分布，则两样本t检验的效果最佳。
4.汽车颜色属于没有特定值或顺序的类别，个性类型也是如此。卡方检验可用于评估分类变量之间的关联。可以针对一张表中的所有颜色和所有个性类型进行此操作，以对“某事正在发生”进行全局评估，也可以通过将数据分为两类，一次针对一种颜色和一种个性类型进行此操作，例如“红色和非红色”，“性格外向和非外向”。
所以答案是选择 1.D 2.F 3.B 4.A
