求指导~~昨天看到一道题涉及了Self Report的使用和measurement at individual and group level，题目如下：
If you want to study the relationship between group helping (altruistic) behaviors within the group and group cohesiveness,
(1) Name two ways you can measure altruistic behaviors by self-report at the individual level? (please write out the item) How would you analyze the data?
(2) Name two ways you can measure altruistic behaviors by other-report at the individual level? (please write out the item) In what way would you collect your data?
(3) Name two ways you can measure altruistic behaviors at the group level.
主要就纠结于第一题问的内容了，这题问的是“讲述两种在个人层面用自报告测量在一个团体内的利他行为与团体凝聚力的关系，并阐述分析方法”吗?即说明两种自我报告的使用方法？我查了查资料一般是有两种，问卷调查和面访。
还有就是想问下，对于individual level和group level,是不是这两个level都是可以用single level model来分析？对于group level，使用single level model是不是就是说all individual level data would be aggregated into group means从而转化为group level，即也同样是single level？
