The key to designing any experiment is to look at what research variables could affect the outcome there are many types of variable but the most important, for the vast majority of research methods , are the independent and dependent variables.
Variables and operational definitions the following module explains the different types of variables in quantitative research and discusses operational definitions of variables. Between the research variables, even though researcher cannot see it these variables are called polit denise f, beck ct nursing research, principles and methods 7th edition pliladephia: lippincottwilliams & wilkins variables in research. In scientific research, scientists, technicians and researchers utilize a variety of methods and variables when conducting their experiments. For instance, age can be considered a variable because age can take different values for different people or for the same person at different times similarly, country can be considered a variable because a person's country can be assigned a value variables aren't always 'quantitative' or numerical.
An operational definition is how we (the researcher) decide to measure our the variables in our study (variable = anything that can be measured) there are usually hundreds of ways to measure a dv (eg behavior) research method used to observe and describe. Dependent variable the variable that depends on other factors that are measured these variables are expected to change as a result of an experimental manipulation of the independent variable or variables it is the presumed effect independent variable the variable that is stable and unaffected by the other variables you are trying to measure.
Key concepts of the research methodology understanding the significance of the scientific method home research research conceptual variables choosing the research method a definition of reliability may be yielding the same or compatible results in different clinical experiments or statistical trials.
This control may involve manipulating existing variables (eg, modifying existing methods of instruction) or introducing new variables (eg, adopting a totally new method for some sections of a class) in the research setting.