RESPROJ LESSON 1.pptx

EXPERIMENTAL RESEARCH DESIGN

TERMINOLOGY

• Independent Variable: The manipulated variable by the researcher (e.g., teaching methods, levels of lighting).

• Treatment Conditions: The specific values of the independent variable (e.g., Traditional, Constructivist; high light, medium light, low light).

• Dependent Variable: The variable observed for changes to assess the effects of the independent variable (e.g., student scores in math, size of plants).

• Extraneous Variables: All other variables in the study that are not independent or dependent variables (e.g., IQ, temperature, fatigue, age, noise, oxygen, soil, fertilizer).

INTRODUCTION

• Experimental research is the most scientifically sophisticated research method, defined as "observation under controlled conditions."

• Focuses on examining the effect of an independent variable on a dependent variable through manipulation and observation.

TRUE EXPERIMENTAL DESIGN

Concept

• True experimental designs allow researchers to control extraneous variables, ensuring that observed effects on the dependent variable are due to the manipulation of the independent variable.

• The goal is to establish causal relationships between two variables.

Essential Characteristics

1. Manipulation: A variable is manipulated to create treatment conditions (e.g., varying levels of lighting to observe plant growth).

2. Measurement: Collect scores from each treatment condition (e.g., measuring light intensity and plant length).

3. Comparison: Scores from different treatment conditions are compared (e.g., growth under different lighting conditions).

4. Control: Control extraneous variables (e.g., oxygen, fertilizer, soil, and water) to avoid influencing results.

Types of True Experimental Designs

• Post-test Only Design: Comprises two randomly assigned groups (experimental and control); treatment is applied only to the experimental group, and outcomes are assessed post-treatment.

• Pretest-Posttest Design: Subjects are randomly assigned and pretested before treatment, followed by a post-treatment assessment.

• Solomon Four-Group Design: Involves four groups with different combinations of pretesting and treatment, minimizing threats to validity.

• Factorial Design: Allows manipulation of two or more independent variables simultaneously to observe their effects.

• Crossover Design: Subjects receive multiple treatments in different orders, allowing for self-control comparisons.

• Randomized Block Design: Controls variability by grouping subjects with similar characteristics.

ADVANTAGES OF TRUE EXPERIMENTAL DESIGN

• Establishes causal relationships effectively, particularly in controlled environments.

• Enables control of conditions not found in natural settings, allowing significant findings in a shorter timeframe.

• Facilitates research in specialized settings, minimizing external pressures.

DISADVANTAGES OF TRUE EXPERIMENTAL DESIGN

• Ethical concerns may limit research on human subjects.

• Challenges in replicating results due to human variability.

• Some human variables may lack valid measurement tools.

QUASI-EXPERIMENTAL RESEARCH DESIGN

Introduction

• Quasi-experimental designs manipulate the independent variable but lack randomization or a control group, limiting their strict experimental control.

• Typically used when random assignment or control groups are not possible.

Main Characteristics

• Involves manipulation of independent variables and observation of effects on dependent variables.

• Lacks one essential characteristic of true experiments (randomization or control).

• Uses quasi-independent variables when complete control is impractical.

Types of Quasi-Experimental Design

1. Nonrandomized Control Group Design: Lacks random assignment but observes outcomes in pretest-posttest scenarios.

2. Time-Series Design: Involves repeated measures over time to assess treatment effects on individuals or small groups.

ADVANTAGES OF QUASI-EXPERIMENTAL DESIGN

• More practical and feasible for nursing research where randomization may not be possible.

• Suitable for natural settings, facilitating casual relationship establishment under real-world conditions.

DISADVANTAGES OF QUASI-EXPERIMENTAL DESIGN

• Limited control over extraneous variables diminishes the reliability of results.

• Absence of control groups weakens claims of causal relationships.

PRE-EXPERIMENTAL RESEARCH

• A weak research design with minimal control over experiments.

• Types include:

  • One-shot Case Design: Observes a single group post-treatment without prior testing.

  • One-group Pretest-Posttest Design: Observes a single group pre and post-treatment but lacks control group.

Thank You

• Presented by: MR. JAYESH PATIDAR

• Source: www.drjayeshpatidar.blogspot.com