Quantitative Research Designs: Descriptive non-experimental, Quasi-experimental or Experimental?

Summary

This video guides viewers in classifying quantitative research designs into descriptive, non-experimental, quasi-experimental, or experimental categories. It explains key factors like interventions, control groups, and random sampling that influence classification. Descriptive non-experimental studies are observational, while quasi-experimental studies lack randomization or a control group. Experimental designs include randomized controlled trials (RCTs), considered the gold standard. The video also addresses common terms like cross-sectional, longitudinal, and convenience sampling, emphasizing their role in study design but not classification. By answering three key questions, viewers can accurately categorize any study.

Takeaways

• 😀 Quantitative research designs are classified into descriptive, non-experimental, quasi-experimental, and experimental categories.
• 😀 To determine the design, ask if the researchers implemented an intervention or manipulation with the participants.
• 😀 An intervention includes things like support groups, educational sessions, or treatments. If there is one, the study could be quasi-experimental or experimental.
• 😀 If there is no intervention, the study is categorized as descriptive non-experimental, which may also be called observational research.
• 😀 Descriptive non-experimental studies include labels like case control, cohort, and correlational studies.
• 😀 To distinguish between experimental designs, check if the study is a randomized controlled trial (RCT), considered the gold standard in quantitative research.
• 😀 Randomized controlled trials (RCTs) include a random sample, control group, and intervention. If these elements aren’t present, the study may be quasi-experimental.
• 😀 A study without a control group is classified as quasi-experimental, where a group does not receive the intervention but is used for comparison.
• 😀 If the sample is not randomly assigned or properly randomized, it is also quasi-experimental. Partial randomization does not count as a true experiment.
• 😀 Terms like cross-sectional (data collected at one point in time) and longitudinal (data collected over time) do not define the overall research design classification. Additional labels are needed to specify the design.
• 😀 Convenience sampling refers to using readily accessible participants, which means the study is not randomized and may be classified as descriptive non-experimental or quasi-experimental, depending on other factors.

Q & A

What are the three main categories of quantitative research designs?

The three main categories of quantitative research designs are descriptive, non-experimental, quasi-experimental, and experimental.

How can you tell if a study is descriptive non-experimental?

A study is considered descriptive non-experimental if there is no intervention or manipulation done to the participants. It is observational in nature.

What defines an intervention in a quantitative study?

An intervention in a quantitative study refers to any action taken by the researcher that directly influences the participants, such as treatments, support groups, or educational sessions.

What is the difference between quasi-experimental and experimental designs?

The main difference lies in the presence of a control group and random sampling. Experimental designs include both a random sample and a control group with an intervention, whereas quasi-experimental designs may lack one or both of these elements.

What are randomized controlled trials (RCTs) considered in research?

Randomized controlled trials (RCTs) are considered the gold standard in quantitative research because they involve random sampling, a control group, and an intervention, ensuring high levels of control over variables.

Can a study still be valid if it is not a randomized controlled trial?

Yes, a study can still be valid even if it is not an RCT. It may be classified as quasi-experimental or descriptive non-experimental, depending on the study's methods and whether an intervention was applied.

What is the role of a control group in a study?

A control group is a group of participants who do not receive the intervention being studied. They are used for comparison to determine the effect of the intervention.

What does it mean if a study is described as non-randomized?

A non-randomized study means that participants were not randomly assigned to groups. This can lead to biases and typically results in the study being classified as quasi-experimental.

How can you differentiate between a longitudinal and cross-sectional study?

A cross-sectional study collects data at one specific point in time, while a longitudinal study gathers data over a longer period, tracking changes over time.

What is convenience sampling and how does it affect study classification?

Convenience sampling involves selecting participants who are easily accessible to the researcher. Since it is not random, it can disqualify the study from being an RCT and may classify it as quasi-experimental or descriptive non-experimental.