Cross Sectional Study Design: The use of cross sectional design is used for the kind of research that collects data on more relevant variables at a single attempt from different kinds of people, subjects or phenomenon. The key feature here is that the data is collected at the same time.
The cross sectional design offers a snapshot of the different variables in the study. It would help to bring forth those variables that are representatives of a cross section of the population. These designs usually depend upon the survey techniques for the collection of data.
Cross Sectional Study Design have key advantages and disadvantages.
The main advantages are:
- It collects data on multiple variables
- Data is collected from a large number of respondents
- Data is collected from varied subjects
- It collects data on attitudes and behaviour
- It aids exploratory research
- It helps to generate relevant hypotheses for future research
- The data from this is useful for many different researchers
The main Disadvantages are:
- Augments chances of error
- Adds the cost as the subjects increase
- Increases cost as there are multiple locations
- Does not measure or evaluate change
- Does not focus on cause and effect
- It does not control independent variable
- It is more time bound
Longitudinal Designs
As the name is indicative, a longitudinal design collects the data over a span of time. The measurement is taken on each and every variable in not just one time frame but over two distinct times. It aids in measuring change and comparing it over time. Time series and panel are two different types of longitudinal designs.
When we talk of the first type, a Time Series Design compiles the data on a similar variable at predefined regular intervals. This is done in a form of aggregate measures of population. There are a lot of uses of Time Series Designs.
- Putting up a baseline measure
- Comparing the changes that have taken place over time
- Keeping a record of the trends
- Predicting trends for the time to come
The presentation of Time Series data is in the form of pictorials like charts and graphs. Analysis and interpretation from these graphs looks for four types of patterns that are identified.
- Long term trends
- Cyclical Variations
- Seasonal Variations
- Irregular Variations
There are some advantages and disadvantages of Longitudinal Designs. These are:
Advantages:
- It is very easy to collect data
- Representation of data in graphs is easy
- Interpretation of data is easy
- It is useful for prediction of short term trends
Disadvantages:
- The approach for data collection changes over a time period
- It is difficult to bring out more than one variable at a certain time
- It needs to be clubbed with qualitative research for explanations
- It relies on the assumption that present trends will remain unchanged
