independent variable

Examples of independent variable in the following topics:

• Experimental Research

  • By creating a controlled environment, researchers can test the effects of an independent variable on a dependent variable or variables.
  • In this example, the independent variable is video game group.
  • The dependent variable, on the other hand, depends on the independent variable, and will change (or not) because of the independent variable.
  • An experiment can have more than one independent variable.
  • Control groups are used to determine if the independent variable actually affects the dependent variable.

• Methods for Researching Human Development

  • This design points to cause-and-effect relationships and thus allows for strong inferences to be made about causal relationships between the manipulation of one or more independent variables and subsequent subject behavior.
  • The correlational method explores the relationship between two or more events by gathering information about these variables without researcher intervention.
  • The advantage of using a correlational design is that it estimates the strength of a relationship among variables in the natural environment.
  • However, the limitation is that it can only indicate that a relationship exists between the variables; it cannot determine which one caused the other.

• Correlational Research

  • Correlational studies are used to show the relationship between two variables.
  • Unlike experimental studies, however, correlational studies can only show that two variables are related—they cannot determine causation (which variable causes a change in the other).
  • A correlation of 0 indicates no relationship between the variables.
  • Sometimes it is not possible to carry out a true experiment for practical or ethical reasons because it is impossible to manipulate the independent variable.
  • Instead, the third variable of education level affects both.

• Surveys and Interviews

  • In this example, the mood induction condition is the independent (manipulated) variable, while participants' responses on the emotion survey is the dependent (measured) variable.
  • Structured surveys, particularly those with closed-ended questions, may have low validity when researching affective variables.

• General Strengths and Limitations of Trait Perspectives

  • One possible proof of this is that several trait theories were developed independently of each other when factor analysis was used to conclude a specific set of traits.
  • While developing their theories independently of each other, trait theorists often arrived at a similar set of traits.
  • Some psychologists argue that the situational variables (i.e., environmental factors) are more influential in determining behavior than traits are; other psychologists argue that a combination of traits and situational variables influences behavior.
  • Such critics argue that the patterns of variability over different situations are crucial to determining personality, and that averaging over such situations to find an overarching "trait" in fact masks critical differences among individuals.

• Psychology and the Scientific Method

  • A hypothesis is a prediction about the relationship between two specific variables.
  • In an experiment a researcher manipulates certain variables and measures their effect on other variables in a controlled environment.
  • Descriptive studies describe the nature of the relationship between the intended variables, without looking at cause or effect.
  • Non-descriptive studies use correlational methods to predict the relationship between two (or more) intended variables.
  • Side by side reasoning involves two independent reasons which can support one conclusion, independent of one another.

• The Five-Factor Model

  • The five factor model was reached independently by several different psychologists over a number of years.
  • Because this model was developed independently by different theorists, the names of each of the five factors—and what each factor measures—differ according to which theorist is referencing it.
  • It is also described as the extent to which a person is imaginative or independent; it describes a personal preference for a variety of activities over a strict routine.
  • Critics of the trait approach argue that the patterns of variability over different situations are crucial to determining personality—that averaging over such situations to find an overarching "trait" masks critical differences among individuals.
  • Factor analysis, the statistical method used to identify the dimensional structure of observed variables, lacks a universally recognized basis for choosing among solutions with different numbers of factors.

• Basic Inferential Statistics

  • The reason the normal distribution is so important is because most inferential statistics are based on the assumption that the variable we are measuring is normally distributed.
  • If our variable is normally distributed, that gives us confidence that if we were to obtain the whole population of observations for that variable, the resulting distribution would also be normally distributed, and therefore the inferences we draw (using statistics) are accurate.
  • Then we would run an independent samples t-test, which would tell us whether there is a significant difference between mean SAT scores for men versus women.

• Allport's, Cattell's, and Eysenck's Trait Theories of Personality

  • Cattell believed it necessary to sample a wide range of variables to capture a full understanding of personality.
  • In the psychoticism/socialization dimension, people who are high on psychoticism tend to be independent thinkers, cold, nonconformist, impulsive, antisocial, and hostile.
  • Eysenck proposed that extroversion was caused by variability in cortical arousal, with introverts characteristically having a higher level of activity in this area than extroverts.

• Defining Intelligence

  • He was a very influential advocate for the concept of non-intellective factors (variables that contribute to the overall score in intelligence, but are not made up of intelligence-related items, including lack of confidence, fear of failure, attitudes, etc.), and he felt that the Binet-Simon scale did not do a good job of incorporating these factors into intelligence. 
  • Fluid intelligence (Gf) is the capacity to think logically and solve problems in novel situations, independent of acquired knowledge.