Guidance on statistical design and data analysis

Posted by Jean Providence NZABONIMPA on May 11, 2012; 11:05am
URL: http://spssx-discussion.165.s1.nabble.com/Guidance-on-statistical-design-and-data-analysis-tp5702790.html

Dear all,
Sorry for my layman questions in statistics. What is the minimum sample sample size to compare two or three groups? Please give me a statistical advice on the minimum sample size. I am looking into methods effects resulting from a quasi-experimental sequential mixed methods design (qualitative and quantitative) using survey questionnaire, semi-structured interviews, and essays. I will compare data from two groups collected at two different times. One group will be subjected to two methods of data collection and another group will be only subjected to one method of data collection. Also, what statistical tests are more appropriate to detect differences in data collected? I will be quantitizing the qualitative data by presence/absence, mentioned/unmentioned, yes/no and compare with survey data. Both qualitative and quantitative tools are designed to collect data on the same concepts.
Your guidance is highly appreciated.
Thanks in advance
Jean Providence