Experimental Method Design

Introduction

Experimental- method design is a collection of a number of different designs of research, which make use of testing that, is both controlled and manipulated to comprehend causal processes. In most cases, one or more variables are used in research and manipulated to understand the kind of effects they have on variables that are dependent. The experimental method is an approach that is scientific and systematic used in research, whereby a researcher manipulates variables and measures and controls any change that occurs in other variables. Experimental research is commonly used in cases where time is a priority and whereby it causes relationships that are causal. It is also common in cases where in a causal relationship consistency exists and in cases whereby the correlation magnitude is huge (Borg, Gall & Gall, 1993). The purpose of this paper, therefore, is to describe a sample population used in an experimental research.

It is essential to note that the main purpose of experimental design is to predict phenomenon. Technically, experiments are constructed so that they can be used to explain certain causation or trends. Experimental research is also essential in any social setting as it helps individuals improve or better their lives. In designing an experimental research, the researcher has to identify the research problem first. After this, they have to construct the experimental design. When constructing the experiment, one has to put in mind a number of aspects. Planning beforehand makes sure that studies are conducted appropriately and that the experimental results reflect or indicate the real world as much as possible (Borg, Gall & Gall, 1993).

Sampling groups appropriately is particularly essential especially when a research has more than one conditions or variables. In most experimental researches, one group usually is used as the control group, while others are measured or tested after they have been exposed to the conditions of the experiment. Deciding on or choosing the sample populations can be done through a number of ways or different techniques of sampling. Pairing, randomization, and quasi- randomization are some of the most commonly sampling techniques used to choose a sample population used in experimental research. For a researcher to obtain valid results, they have to reduce or decrease errors in sampling. To minimize most errors such as random errors, most researchers adjust the size of their samples. There are numerous sampling techniques available to experimental researchers (Cochran, 1977).

Some of these include such techniques as probability sampling, simple random sampling, non- probability sampling, systematic sampling, convenience sampling, stratified sampling, cluster sampling, disproportional sampling, sequential sampling, quota sampling, judgmental sampling, and snowball sampling. A sample population for an experiment, for example, can be defined by sex, age, weight, race, ethnicity, eating habits, and any other trait or characteristic that can be used to define the human race. A sample population can be made of men only another can be made of a mixture of both sexes, and another one can be made of women. The same populations can specify one race while the other can integrate all races, and another can utilize only two or three races. The characteristics of a sample population are determined by the type of research the researcher is carrying out and the kind of questions in the research (Cochran, 1977).

Conclusion

Experimental research seeks to answer certain questions about certain trends or causations. Fr such a research to be meaningful and valid, the design has to be carefully chosen with the appropriate design, questions and sample population.

References

Borg, W. R., Gall, J. P., & Gall, M. D. (1993). Applying educational research (3rd ed.). New York: Longman.

Cochran, W. G. (1977). Sampling techniques (3rd ed.). New York: Wiley.