Types of Quantitative Research Designs~GM Lectures

Overview of Quantitative Research Designs

Types of Quantitative Research

• Quantitative research is divided into two major types: experimental and descriptive non-experimental.

• Experimental research is further classified into true experimental and quasi-experimental designs. Descriptive non-experimental research includes survey and correlational research, as well as classifications based on time dimensions like cross-sectional and longitudinal studies.

True Experimental Research

• True experimental research aims to determine causal relationships among variables, relying on statistical analysis to validate hypotheses. It is considered the most accurate type of experimental design.

• This type involves a control group and a test group, with variable manipulation and random selection of participants being key characteristics. The study is conducted in a controlled setting with an intervention present.

• An example provided illustrates how classical music affects students' academic performance, comparing results between a control group (no music) and an experimental group (music played). The conclusion suggests that classical music positively impacts academic performance.

Quasi-Experimental Research

• Quasi-experimental research also seeks to determine causal relationships but differs from true experiments in that participants are not randomly assigned; it typically includes pretests and posttests.

• An example discusses a reading intervention program for students with low comprehension levels, starting with a pre-test to identify participants who need help before undergoing the intervention program followed by another posttest to assess effectiveness.

Similarities and Differences Between Experimental Designs

• Both true experimental and quasi-experimental designs aim to establish causal relationships, involve interventions, manipulate variables, and are conducted in controlled settings. However, they differ in participant selection methods (random vs non-random), use of pre-tests (optional vs required), and presence of control groups (present vs absent).

Types of Non-Experimental Research Designs

Survey Research

• Survey research gathers evidence on people's knowledge, opinions, attitudes, and values regarding various issues using questionnaires or interviews without manipulating variables or applying interventions.

Research Design in Non-Experimental Studies

Responsibilities of Researchers in Survey Research

• Researchers focus on recording and tallying responses, analyzing data, and drawing conclusions based on findings.

• In a given example, 75% of respondents answered "yes," indicating majority support for mass testing.

Correlational Research Overview

• Correlational research interprets the degree of relationship between two or more variables using statistical data without controlling or manipulating them.

• It does not establish cause-and-effect relationships; rather, it identifies associations between variables.

Conducting Correlational Research

• A researcher hypothesizes no significant relationship between online gaming and critical thinking among students. Participants are selected based on their online gaming habits.

• The study involves assessing participants' gaming habits and critical thinking levels to analyze potential correlations without intervention.

Types of Non-Experimental Research Designs According to Time

Cross-Sectional Research

• This design gathers data at a single point in time, focusing on comparisons across different variables of interest. An example includes studying spending trends between men and women in their 30s.

• Findings indicate that women tend to spend more than men within this demographic group, allowing for comparative analysis across age brackets.

Longitudinal Research

• Longitudinal research collects data at multiple points over time to compare datasets effectively; an example is studying the effects of antiretroviral medicines on HIV-positive patients over time.

• Participants' viral loads are monitored before and after treatment to assess the effectiveness of the medication over an extended period.

Comparing Cross-Sectional and Longitudinal Research

Similarities:

• Both designs are observational and involve comparing data sets without manipulation or intervention.

Differences:

1. Data Collection Timing: Cross-sectional research collects data at one point while longitudinal research does so over multiple periods.

2. Duration: Cross-sectional studies are typically shorter in duration compared to longitudinal studies which may take years to complete for comprehensive results.

Experimental vs Non-experimental Research Designs

Similarities:

• Both types utilize numeric data and statistics.

Differences:

1. Variable Manipulation: Experimental designs involve manipulation of variables whereas non-experimental designs do not.