Homework Writing Help on The Scientific Variables

The Scientific Variables

The aim of scientific studies is to establish the cause or effect relationship between two or more factors. Such factors are scientifically referred to as experimental variables. A variable is an item or condition whose status can change with respect to the changes in other factors (Patricia 1). Experimental variables can either be the known or unknown factors that may change in the course the study. In addition, variables include both the experimental changes that are intentionally studied in the experiment, and those that do not interest the researcher. This essay discusses the differences and similarities between the dependent, independent, extraneous, and confounding variables.

The Dependent and Independent Variables

Dependent and independent factors are the basic variables analyzed in every experiment. Scientists at every level of study are likely to deal with these two categories of variables. An independent variable is a factor that the experimenter alters or sets the value in order to measure its effects on another factor (Patricia 3). On the contrary, the dependent variable is the factor that is anticipated to change with the changes made on the independent variable. The experimenters vary the value, nature or status of the independent factors to measures or assess the effect on the dependent variable. For example, in an experiment to study the impact of time spent spending on the student’s score, the variables are ‘the time spent studying’ and the ‘the student’s score’. In this case, the time spent studying is independent variable while the student score is the dependent variable. In such an experiment, the experimenter may vary the time spent spending to evaluate the impact on the score, but cannot vary the scores to estimate the time spent studying.

The major similarity between the dependent and independent variables is that both categories interest the researcher. As Patricia (3) explains, both independent and dependent variables have equal weight in the study since they are the subject of the study. The aim of the study is either to find out whether there exist a correlation between the dependent and independent variables or to quantify the known correlation between the two. Therefore, independent and dependent variables are the central focus of the study, without which the study may not be substantive.

The Extraneous and Confounding Variables

In a typical experiment, the analysts point out the precise factors they intend to study. However, there are also other variables that are not being studied, but influence the outcome of the study. As Nadine explains, factors that are not intentionally studied despite their effect on the experiment are referred to as extraneous variables (education-portal.com). In an experiment to assess the impact of time spent studying on the candidate’s score, for example, extraneous factors could be the candidate’s intelligence, level of anxiety or the toughness of the exam. There is a special case of extraneous factor that changes systematically with the studied variables. These systematic extraneous factors are known as the confounding factors.

A standard experiment may have several extraneous variables, in addition to the studied dependent and independent variables. The researcher knows some extraneous variables while others are unknown, despite the fact that they may influence the outcome of the study. Ordinarily, extraneous variables have no significant impact and are often ignored in the study. However, Nadine elaborates that it is necessary to recognize and consider the confounding variables as they add to the credibility of the study (education-portal.com). Researchers use the evidence from previous studies as well as the logical reasoning to identify extraneous variables that are capable of becoming confounding variables. For example, if there are previous studies that evaluated and found that the level of student’s anxiety affects their performance, then anxiety is a potential confounding factor in the study of impact of time spent studying. On the other hand, the researcher may argue logically that the student’s intelligence can impact on their score.

Extraneous variables (including the confounding variables) are further categorized into three different groups. As Nadine outlines, extraneous variables can be grouped into physical or situational, personal or the researcher’s extraneous variables (education-portal.com). The physical extraneous variables refer to the changes that emanate from the physical situation of the subject. In the example of the time spend studying and the student’s score, the subject is a student. Physical extraneous variable may occur if students in a certain classroom or block appear to perform differently. The second category, the personal extraneous variable, includes the changes that are attributed   to the subject’s traits. For instance, student’s intelligence in the above example is a personal variable. The final category, referred to as the researcher variables, is the changes invoked by the researcher. For example, the researcher may make different presentations while studying various groups.

Extraneous variables relate with the studied variables in that the unstudied factor could influence the experiment as either a dependent or the independent variable. In the study above, for example, other unstudied variables may present similar impact as the time spent studying (independent variable) as well as the student’s scores (dependent). For instance, the students’ anxiety is a dependent extraneous variable while the exam content is the independent extraneous variable.

The variation between extraneous, dependent and independent variables depends on the aim of the experiment. For instance, an extraneous factor in one experiment could the dependent or independent variant in the other. As Nadine elaborates, it depends on what the experimenter is studying at a particular experiment (education-portal.com). Further, a confounding factor is simply an extraneous factor whose change is consistent with the studied factors. However, not all extraneous variables can become confounding factors as it all depends on the subject of the study. Although confounding factors are not part of the study, they can be used in the analysis of the studied factors. They offer a wide range of alternative explanations as to why the experimental results are the way they are. Although confounding variables may be necessary for the interpretation of the link between dependent and independent variables, extraneous contribute to systematic errors in the study. Therefore, the researcher should identify and control any extraneous variable.

In conclusion, variables can be classified into two broad categories; intentionally studied variables and the variables that are not studied. The studied category is made of the dependent and the independent variables while the extraneous variables fall under unstudied. The confounding variables are a special case of extraneous variable whose change is consistent with the dependent and the independent factors. The major similarity between dependent, independent, extraneous and confounding factors is that their statuses may vary with the changes of other factors in the experiment.

Works Cited

Nadine, James.What are Variables in Science? – Definition, Types & Examples” Education Portal. N, dat. Web. 19 December 2014. http://education-portal.com/academy/lesson/what-are-variables-in-science-definition-types-examples.html#lesson.

Patricia, Teresa. Dependent and Independent Variables – Unabridged Guide. Dayboro: Emereo Pub., 2012. Print.