Hi! I’m Kylie Nicholas, a managing consultant at IG and your IG-Ologist for the month of May! This month’s IG-Ology topic is longitudinal studies. These are studies that measure impact over multiple years by following the same group over a period of time. This can be done in different ways—for example, the Olmstead Quality of Life Survey measures changes in the lives of Minnesotans with disabilities as the State works to increase autonomy and integration of this population. To do this, we are tracking changes in a sample of the study group. We recently completed the baseline survey, and will soon check back in with a portion of the survey participants. Similarly, the Minnesota Youth in Transition Database study involves keeping in touch with youth as they age out of foster care—case managers survey the youth at age 17, and we keep in touch with the youth and follow up with surveys at ages 19 and 21. Approaches to longitudinal studies vary—but my experience has taught me the importance of considering the characteristics of the population of interest when deciding how to design your study.