Fundamentals of Experiment Design - Experimental Design

Experimental Design

Experimental design is the process of planning an experiment with the goal of obtaining relevant and high-quality information that aligns with the research objectives. Proper design is crucial to maximize the efficiency and quality of collected data and to ensure that the conclusions drawn from the data are valid and reliable.

Why Design is Necessary

1. Eliminate Bias: Well-designed experiments can help minimize or eliminate bias, including systematic errors that can compromise the validity of results.
2. Improve Precision: By controlling factors that might influence outcomes, experimental design can enhance the precision of results and ensure that the observed effects come from the variable under study, not other factors.
3. Generalize Results: Good experimental design allows researchers to generalize their findings to a larger target population. In other words, the results of the experiment can be applied to other situations and individuals beyond the ones studied.

Objectives of Experimental Design

1. Select Influential Variables: The goal of experimental design is to select control variables (X) that most influence the response (Y). By understanding which variables have a major influence, researchers can focus on these variables in further research.
2. Approach the Expected Value: Experimental design can assist researchers in selecting a set of control variables (X) that produces response values closest to the expected value.
3. Reduce Response Variance: Experimental design can also assist in selecting a set of control variables that result in the smallest response variance (σ²), meaning more consistent results.
4. Reduce the Influence of Uncontrolled Variables: In an ideal situation, researchers would be able to control all variables that might influence the outcome. However, this is often impossible. Therefore, good experimental design also involves the selection of a set of control variables that result in minimal influence from uncontrollable variables. 

Steps in Research Activities (Experimental Procedures to Achieve Objectives)

1. Selecting a Problem: This step requires sensitivity and a good understanding of the research field. You need to identify and understand the problem to be studied. For example, if you're trying to figure out why farmers' corn crops aren't maximizing yield, you need to determine whether this is due to soil infertility, improper farming methods, or improper fertilizer use.
2. Preliminary Study: This step involves exploratory research to gather more information about the topic to be studied. You need to review related literature and previous research findings to inform your experiment.
3. Formulating the Problem: You need to clearly and specifically formulate your research problem. This step involves identifying concepts or theories that can be used to solve the problem. For instance, you might formulate that applying manure fertilizer in the right dose can improve soil fertility.
4. Formulating a Hypothesis: This step involves creating a hypothesis statement based on previous research findings and existing theories. This hypothesis will form the basis of your experiment.
5. Selecting an Approach: You need to choose the research method to be used, as well as determine the type and kind of research most suitable for the identified problem. This selection will greatly determine your research's variables, objects, subjects, and data sources.
6. Identifying Variables and Data Sources: You must determine your research variables and where the data will be obtained from. These variables should align with your research objectives and hypothesis.
7. Determining and Arranging Instruments: You need to determine the type of data required and where it will be obtained from. You also need to select an appropriate data collection method, such as observation, interviews, or questionnaires.
8. Collecting Data: This step involves data collection in accordance with the determined method.
9. Data Analysis: The collected data need to be analyzed carefully and with a deep understanding of the data. The analysis technique used will be greatly determined by the type of data collected.
10. Drawing Conclusions: By considering all the data and analysis results, you will draw conclusions from the research. You need to be honest in assessing whether your hypothesis has been proven or not.
11. Compiling a Report: The final step involves writing and organizing the research report. The report must be written in correct and good language, and it should cover all aspects of the research, including methodology, findings, and conclusions.

Objectives & Goals of the Experiment

1. Purpose of the Experiment: The purpose of an experiment is the fundamental reason why the experiment is being conducted. In a scientific context, the purpose of an experiment is typically focused on efforts to gain new knowledge or deepen understanding of a phenomenon. This purpose can also be referred to as an endeavor to achieve the goals of the experiment. For instance, the purpose of an experiment could be to understand how a certain object or system responds to various conditions or specific variables. In many experiments, these conditions or variables are deliberately created or introduced, for example through certain treatments or environmental settings.
2. Goals of the Experiment: The goals of an experiment refer to the anticipated or targeted outcome of the experiment, which is typically a manifestation or accomplishment of the experiment's purpose. In other words, the goal is the result that one aims to achieve from the research or experiment. For example, if you are conducting an experiment to understand the adaptation of various soybean varieties in peatland, your experimental goal might be to find the most adaptive soybean variety in peatland.

So, in research or an experiment, the purpose is why you are doing it, while the goal is what you hope or aim to achieve as a result of the experiment.