Components of Research 2.2

Causation Causation is the belief the events occur in predictable ways and have a causal effect on one another Multiple Causation: belief that an event occurs as a result of several variables working together

Variables Variable: a characteristic that is subject to change There are two types of variables: quantitative qualitative

Variables Quantitative variables characteristics that can be measured numerically examples: 65% of men watch football on Sundays 3 million people live in Chicago There are 15 major gangs in Los Angeles

Variables Qualitative variables Characteristics that are defined by being placed into a category “either/or” “yes/no” examples: you are a male or female you are a frosh, soph, junior or senior do you drive

Variables Independent variable: Dependent variable: Characteristic that causes change Dependent variable: Characteristic that reflects change Intervening variable: Variable that changes the relationship between the independent and dependent variables

Variables A teacher documents that the more sleep a student has before a test the better grade she will earn. What is the independent variable? amount of sleep What is the dependent variable? grade that is earned

Variables Kevin gets frustrated at his wife when they are late to functions because she takes too long to get ready. What is the independent variable? the time my wife ready to leave What is the dependent variable? Kevin’s frustration level

Variables If Susie finishes her chores by Wednesday she is allowed to extend her curfew by a half-hour. What is the dependent variable? extension of curfew What is the independent variable? the day she finishes her weekly chores

Correlation Correlation = measure of the relationship between two variables There are 2 types of correlation Positive Negative

Correlation Positive Correlation When the independent and dependent variable change in the same direction Do not apply value judgments – positive does not mean “good” Examples: Increased studying = better grades Increased number of gangs = increased crime More you eat = increase in weight gain

Correlation Negative Correlation When the independent and dependent variable change in opposite directions Do not apply value judgments – negative does not mean “bad” Examples: Increase in healthy diet = decrease chance of illness Increase in fire engines = decrease in response time More time spent with friends = decrease in grades

Causation & Correlation 3 standards must apply to show causation: Variables must be correlated All possible factors must be taken into account A change in the independent variable MUST occur before a change in the dependent variable

Causation & Correlation Spurious correlation: an apparent relationship between two variables which is actually caused by a third Example: Juvenile delinquency declines when church attendance increases Is this negative correlation related?

Causation & Correlation 1st standard: can’t determine with out other applying other 2 standards 2nd standard: age is a factor teens attend church less than pre-teens; teens are more likely to commit crimes than pre-teens 3rd standard: does attendance stop before delinquency starts does delinquent behavior occur before attendance stops does this occur at the same time

Causation & Correlation Since it is impossible to apply all 3 standards there is no correlation between church attendance and juvenile delinquency