Dear list, I feel that I have to contact you for help with the data set I collected. It concerns longitudinal data from acoustic measurements conducted at monthly invervals during the development of a group of children. In the synchronic perspective, I have found that it is highly unlikely that the data is normally distributed. Furthermore, other studies have shown a decreasing variance with increasing age. So, what I want to ask you is: 1) What do I do with this data. Is it possible to do statistical analysis on this? 2) What approach do you recommend? What are the potential draw-backs? 3) Do you have some litterature suggestions for me? 4) If there is something that I can do, is it implemented in R? I'm sure that you can tell that I would be happy for any help I could get on this issue. /Fredrik Karlsson