When taking time into account, there are two different survey types longitudinal and cross-sectional. Cross-sectional surveys only look at one point in time. The issue with these is that studies are not always a stagnant issue. Some need to be evaluated over time. This is where longitudinal surveys excel. There are three longitudinal surveys; trend, panel, and cohort. And one other similar type, the retrospective survey.
Trend surveys are what you think they are. They track different trends. Trends, by nature, change over time. Making it impossible to use a cross-sectional approach. The way they work is they ask questions and then keep following up to see how the answers change. Those that participate are not always the same each time. They try and keep the demographic range of the participants as similar as possible to the last survey. One company that does this exceptionally well is Gallup. They collect data that has to do with attitudes and behavior. Both of these can change over time. Tracking them can help improve places of work, schools, and businesses.
Panel surveys have a lot in common with trend surveys. They are asking the same question over time. The significant difference is that they are asking the exact same people each time. As you can imagine, this is not the easiest to set up. Tracking the same thousand people for years can take a lot of resources and effort. One famous study is the Youth Development Study. Following a group of adolescences into adulthood to see how their early life has affected them. For years, they have collected this data. And they plan on continuing through more generations. A lot can be learned through panel surveys.
Cohorts surveys like the previous two are asking the same questions of time. This time they are singling out one group of people. Instead of trying to get a range of people that want everyone surveyed to be similar. This could be an age group, race, gender, or anything that groups people. An example of this could be looking to see how long millennials feel that they should be living at home.
Retrospective surveys are a mix between a cross-sectional and longitudinal. Like a cross-sectional, they are only given one time. Like a longitudinal, they are tracking something that happened over time. They will ask the respondent to provide information on events that occurred over time. Looking at things that have happened over time, but only being questioned one time. An example would be asking where they spent their last ten Christmas’s. An issue with this type is the participant not being able to remember things correctly from the past.
Retrospective surveys would be the easiest to accomplish since you only have to meet one time. Trend and cohort may take more time, but able to use different participants makes it less of a commitment. Panel surveys can provide very valid data, but it will be the hardest to execute.