多选题In statement 2, "effectiveness of performance of subjects" is______. A、independent variable B、dependent variable C、mediator variable 无解析多选题Which of the following is the most common purpose of a Pearson’s correlation analysis? A、Differences between groups. B、Differences between variables. C、Relationships among groups. D、Relationships among variables.简答题Which of the following is the coremenu of SPSS? A、File. B、Analyze. C、Edit. D、Data.简答题When we want to survey students’ proficiency levels in a particularly large community, we should choose ______. A、simple random sampling B、cluster sampling C、systematic sampling D、snowball sampling简答题When we want to study a population where the subjects are particularly hard to identify or reach, we should use ______. A、simple random sampling B、convenience sampling C、stratified sampling D、snowball sampling简答题We type each of the 1,000 students’ names on cards, shuffle the cards, then randomly pick 200. It is ______. A、systematic sampling B、stratified sampling C、simple random sampling D、convenience sampling多选题In statement 2, "the sex of the subject" is______. A、independent variable B、dependent variable C、mediator variable 无解析多选题In statement 1, "English learning outcome" is ______. A、independent variable B、dependent variable C、mediator variable 无解析多选题Which of the following is not a characteristic of ANOVA? A、Can be used only with two groups. B、Often requires post hoc tests to identify locations of differences. C、Tests for differences between means. D、F-test is used to report results.简答题We want to sample 100 second language learners and the population consisted of 50% Chinese, 30% Iranian, and 20% Korean. A ______ is appropriate. A、stratified sampling B、systematic sampling C、simple random sampling D、convenience sampling多选题Which of the following is not a descriptive statistic? A、Correlational analysis. B、Frequency distribution. C、Mean. D、Standard deviation.简答题We have a population that only has N = 100 people in a systematic order and we want to take a sample of 20 through ______. A、simple random sampling B、clustering sampling C、systematic sampling D、snowball sampling多选题In statement 2, "the sex of the researcher" is______. A、independent variable B、dependent variable C、mediator variable 无解析多选题The t-test is used to ______. A、describe relationships between variables B、examine differences among three or more groups C、test for a significant difference between the means of two samples D、test the power of a statistical procedure多选题In statement 1, "varieties and frequency of the strategy use" is______. A、 independent variable B、dependent variable C、mediator variable 无解析