Something few researchers consider is how the passage of time may affect some research studies. This lesson explores a few different types of studies and how a researcher has to take the dimension of time into consideration when planning the whole experiment.
Nothing is constant. It would be really nice to freeze everything following a major event and then deal with each change one at a time.
There is even a phrase in Latin, ceteris paribus, which means ‘all things held constant.’Unfortunately, you can’t really hold everything at a standstill while you focus on one thing. Real life and real experiments have to happen in real time. Sorry for the repetition, but it is kind of what this lesson is all about. What does this mean specifically when you’re doing research? It means that time is not standing still. It means that all the distractions and issues that happen in the real world are happening to your participants.
For instance, if you need to look at how some participants change over time, you need to be aware that some of your participants may die. It’s not pretty, but it’s possible. Other times huge events can occur, like terrorist attacks or national tragedies, that can distract people so much your results will be skewed.In this lesson, we will discuss how time affects three particular types of research designs: cross-sectional, longitudinal and case studies.
Before we get into the nitty-gritty, cross-sectional designs use sampled groups along a developmental path in an experiment to determine how development influences a dependent variable. This is where you’re interested in how something changes as it develops, and typically this means taking children and adolescents of different ages and testing to see how they’re different.Maybe you think age has something to do with increased anger control, or maybe you think age is irrelevant in mathematical abilities.
You could use a cross-sectional study to address these questions.Time comes into play here in how it affects your participants over the course of their lives. Since cross-sectional studies examine samples along a continuum, the individual’s experience up until that point can be very different.For example, if you look at the life events of people who are:
- 100 years old: World War II and the Great Depression may play a strong part in their lives
- 75 years old: May be impacted by Sputnik and the Space Race
- 50 years old: May have been shaped by the end of the USSR
- 25 years old: Have computers which will likely factor into their development
While the oldest have experienced all of these events, the youngest didn’t experience the earlier ones. Equally important, the older individuals did not experience the more recent events in the same way as the younger generations. There are kids now who have never known the world without computers! The passage of time has brought about many new events and each generation experiences these events differently.
So how do you account for this? Typically, age difference is an understood phenomenon and a limitation of the cross-sectional design. Generations of people aren’t the same.
A quick definition of a longitudinal design is a research study where a sample of the population is studied at intervals to examine the effects of development. This means you have a sample of the population and you study them periodically throughout their lives.
After your tests, you release them back into their natural habitat and then a few weeks, months or years later, you call them up and test them again to see if there are any differences. Sometimes you can call them back two, three or more times.As time passes, people develop and change, and your entire study is based on those changes. Without the time aspect in this study, you wouldn’t really have a longitudinal design; you would just have a regular experiment.In a longitudinal design, you are focusing on the development as time passes. You need to report and focus on how much time has elapsed between specific experiments because this can become an important area later in your discussion. For example, if you checked every five years on developing children, then a lot can happen between each check-in.
With adults, while a lot happens in five years, you don’t see the dramatic developments you do with kids. So, to account for time in your longitudinal design, you want to:
- Record the time intervals
- Inform the reader of what major events may have occurred in that time
- Describe your reasons for selecting specific intervals of time for your study
Briefly, a case study is a detailed recording and analysis of an individual or group. Case studies often occur in unique cases or situations where you don’t have enough people to run a full experiment or study on. For instance, Phineas Gage is a famous case study subject. He was a man who had a metal rod blasted up through his skull, just below his jaw, up through his eye and out the top of his forehead and survived.Time with case studies can work for you and against you. Looking at Gage, we have a man who has experienced a traumatic brain injury.
Descriptions of his condition have him vomiting up blood and brain material. However, with a doctor at his side, the progression of his brain damage could be studied as it attempted to heal itself. Time is working with the doctor to let him understand what happens to a person following this cataclysmic blow to the head.Time, as an element, allows a researcher to see the growth and development or breakage and decay over time. Without the dynamic element of time in the study, you might as well just be looking at preserved brains.
Another facet of time is working against the researcher. In our Gage example, he could have died at any moment due to the trauma to his brain. Or, as what actually happened, Gage moved away and traveled with the circus and eventually died due to a brain related issue many years later.In a broader sense, a case study often happens in real time and cannot be replicated. A researcher could not create a Gage II, so the researcher would need to work rapidly and efficiently with the Gage he had.
To this end, time works against the researcher because you cannot take back and redo something if it goes wrong. Time and the case study only progress forward.
A researcher needs to understand how time will influence his or her study. In cross-sectional designs, which use sampled groups along a developmental path in an experiment to determine how development influences a dependent variable, the time element affects samples drawn from different age groups. In longitudinal designs, a sample of the population is studied at intervals to examine the effects of development.
In this case, time is an integral part of the study and should be reported with accuracy.In a case study, which is defined as a detailed recording and analysis of an individual or group, time can be on your side, such as when you’re curious about how someone changes, heals or develops. Or time can be an enemy to your study because patients can become ill, move away or grow out of something, which would disqualify your participant.
After completing this lesson, you should be able to:
- Define cross-sectional design, longitudinal design and case study
- Explain how time can influence case studies, longitudinal designs and cross-sectional designs