STA630 Final Term Short Notes 2025 by Taniya

Sta-630 Short Notes Final Term 2025 BY Taniya

Lesson 19: Research Design: A Simple Explanation

A research design is a detailed plan that explains how to collect and analyze data. It works like a roadmap, guiding the researcher through the research project.

The design includes key decisions and elements such as the purpose of the study, units of analysis, time dimension, observation methods, sampling techniques, data collection tools, and how the data will be processed and analyzed. Let's look at these elements in simple terms.

Purpose of the Study · Types of Research · Exploratory Research

This type is used when the researcher is trying to understand something new. It involves exploring possibilities and gathering initial information.

Descriptive Research

If the study is about answering questions like " Who?", " What?", " When?", " Where?", or " How much?", it is descriptive. For example, studying what crimes are committed, when they happen, and who commits them.

Explanatory Research

This type seeks to explain why something happens. For instance, understanding why crime rates are higher in one area than in another.

Moving Beyond Exploration

In most cases, after the initial exploration, the study moves to a more formal stage where researchers focus on either description or explanation.

Descriptive Studies: Focus on describing events or situations. Explanatory Studies: Focus on identifying relationships and understanding how one variable influences another.

For example:

Descriptive: What are the types of crimes in a city?

Explanatory: Why do certain crimes occur more frequently in specific neighborhoods?

Levels of Complexity in Research

As research becomes more detailed, it often includes hypothesis testing, advanced data collection methods, better sampling designs, and sophisticated data analysis

Types of Explanatory Studies

Causal Studies

These are conducted to identify cause-and-effect relationships. For example, proving that a certain policy reduces crime rates.

Correlational Studies

These focus on finding connections between variables, without establishing direct cause-and-effect. For example, exploring the link between education levels and crime rates.

Deciding the Type of Study

Researchers decide early whether their study will be causal or correlational. This choice affects how they collect data:

Surveys are common for gathering broad information. Experiments are used to test cause-and-effect relationships.

In short, the purpose of the study shapes the entire research process, from data collection to analysis.

2. Unit of Analysis

The unit of analysis refers to the main focus of the study and the level at which data will be collected and analyzed.

Key Points:

Individuals: When the research focuses on personal characteristics, like how to improve employees' motivation, the unit of analysis is the individual. Dyads (Two-Person Groups): In studies like husband-wife relationships or teacher-student interactions, the unit of analysis is the two-person group. Groups: When studying group effectiveness, the data from individuals in a group is combined to analyze group-level outcomes. Departments or Organizations: If comparing departments, the department becomes the unit of analysis, and individuals within it are treated as a single data source.

Unit of Observation and Analysis:

Sometimes, data is collected at the individual level but analyzed at a higher level, like families or groups. For example, voting intentions may be observed in individuals but analyzed to study political differences within families.

3. Time Dimension

Time plays a key role in how data is collected.

Types of Studies:

Cross-Sectional Studies: Data is collected at one point in time, providing a "snapshot" of the situation. Example: A survey conducted over a month. Longitudinal Studies: Data is collected over a longer period to track changes. Example: Studying employee behavior before and after a management change.

Variations of Longitudinal Studies:

Panel Studies: Repeated observations of the same group over time. Cohort Studies: Observations of a specific subgroup with a shared characteristic, like age or experience.

4. Researcher Control of Variables

The way a researcher handles variables determines the type of study.

Types of Research Design:

Experimental Design:

o The researcher manipulates variables to establish cause-and-effect relationships. o Conducted in two settings: Field Experiments: Natural environment with minimal interference. Lab Experiments: Controlled environment with strict variable management.

Ex Post Facto Design:

o The researcher observes existing variables without manipulation. o Examples include surveys where data is analyzed as it is.

5. Mode of Observation

Data collection methods depend on the type of study:

Surveys: Gathering information from respondents through interviews or questionnaires. Experiments: Testing variables in controlled or natural settings. Case Studies: In-depth analysis of specific cases or events. Focus Groups: Discussions to gather diverse opinions.