Longitudinal Study

A longitudinal study captures data over a period of time (days, week, months, or years) to understand the long-term effects of changes in products, processes, or environment.

Many usability methods like usability testing focus on initial use (learnability). Longitudinal studies focus on long-term effectiveness and satisfaction. A longitudinal study involves the repeated observations or examination of a group of users over time, at regular intervals, with respect to one or more study variables. Longitudinal studies are mainly done in order to follow changes in perception, behaviors, attitudes, and motivation of use. Such studies may be conducted over the duration of anywhere from a few days to several decades. Longitudinal studies can employ a range of methods including diaries, participant observation, critical incident reports, data logging, and repeated interviews.

How To

In order to do a longitudinal study, the following general steps should be followed:

• Identify research questions, which are not well addressed in current cross-sectional studies or even not considered at all.

• Derive a hypothesis from this research question.

• Choose a methodology to test the hypothesis. Longitudinal studies can employ a variety of methods including diaries, participant observation, critical incident reports, data logging, repeated interviews, and repeated controlled experiments in laboratory setting.

• Collect data.

• Define relevant methods for data analysis and analyse data. It is important to note that data in longitudinal studies may be more voluminous than in cross-sectional studies.

• Repeat the study at least two times, at a given time interval.

Tips

• Ensure that variables are kept consistent during the whole duration of the longitudinal study. Otherwise all that will be tested will be the learnability of the system.