Category: Research Methods

There are two types of time dimensions that can be used in designing a research study.

1. Cross-sectional research takes place at a single point in time.
   • All tests, measures, or variables are administered to participants on one occasion.
   • This type of research seeks to gather data on present conditions instead of looking at the effects of a variable over a period of time.
2. Longitudinal research is a study that takes place over a period of time.
   • Data is first collected at the outset of the study, and may then be gathered repeatedly throughout the length of the study.
   • Some longitudinal studies may occur over a short period of time, such as a few days, while others may take place over a period of decades.
   • The effects of aging are often investigated using longitudinal research.

http://psychology.about.com/od/researchmethods/ss/expdesintro_3.htm

People often confuse the terms theory and hypothesis or are not quite sure of the distinctions between the two concepts. As a psychology student, it is essential to understand what each term means, how they differ, and how they are used in psychology research.

A theory is a well-established principle that has been developed to explain some aspect of the natural world. A theory arises from repeated observation and testing and incorporates facts, laws, predictions, and tested hypotheses that are widely accepted.

A hypothesis is a specific, testable prediction about what you expect to happen in your study. For example, an experiment designed to look at the relationship between study habits and test anxiety might have a hypothesis that states, "We predict that students with better study habits will suffer less test anxiety." Unless your study is exploratory in nature, your hypothesis should always explain what you expect to happen during the course of your experiment or research.

While the terms are sometimes used interchangeably in everyday use, the difference between a theory and a hypothesis is important when studying experimental design. Some important distinctions to note include:

A theory predicts events in general terms, while a hypothesis makes a specific prediction about a specified set of circumstances.

A theory has been extensively tested and is generally accepted, while a hypothesis is a speculative guess that has yet to be tested.