This list is not exhaustive. I excluded, for example, the obvious combination of #2 and #3, which in statistics is sometimes called “panel” data analysis. There is also comparative statics, which is like taking cross-sectional studies taken at two different times (like snapshots) and comparing them. The object of investigation is called the explanandum, more commonly known as the dependent variable (Y).
These correspond to the different meaning of the phrase ‘I KNOW’. Observations say as much about the observer as they do that which they observe.
The Vocabulary of Science Dr. John Bradford
Three types of Studies• There are 3 different types of studies that correspond to 3 different sorts of dependent variables (Y), or objects of investigation…1. Case study (what causes an event or condition) – Often we aren’t interested in Y itself as a fact or event, but changes in Y across time (longitudinal study) or differences in Y across space (cross-sectional study).2. Cross-sectional study (comparison across space)3. Longitudinal study (comparison across time)
Levels of Knowledge1. Descriptive/factual/observational- report data. – I know it because I saw it or heard it, and if someone else were there, they would have heard or seen the same thing.2. Inferences or Assumptions- – Statements made about something we don’t know, on the basis of what we do know. Most common form of knowledge.3. Evaluations/Judgments: – An expression of approval or disapproval to assumptions we made, whether or not it is based on something we have seen or heard. – Example: “John is a total jerk!” – They do not convey why we feel the way feel. Abstract judgment words are more about selves and the hidden feelings we want to express.
What’s a Good Explanation?• “A scientific theory should be as simple as possible, but no simpler.” - Einstein• This idea that (all other things being equal) the simpler of two theories is the better theory, is called the principle of parsimony, or ‘Occam’s razor’• Question: Can you think of reasons why a simpler explanation might be a better explanation?
Three Simple Steps to Social Science (easier said than done)STEP 1: Select some concepts of interest (variables)STEP 2: Posit (suggest) some relationship between these concepts (Hypothesis)STEP 3: Test these suggestions empirically to see if they are right.
Concepts and Constructs• Concept: a label that is applied to things with similar characteristics or attributes; a generalization, or category.• Constructs: an abstract concept; words used to describe things that exist analytically (in our minds) but are not directly observable or perceivable. – Examples: Racism, love, economic depression, loyalty, etc.
What are Variables?• Variable: something of interest to a social researcher.• Variables have two characteristics: 1. It is thought to influence or be influenced by another thing. 2. A variable is some attribute of a category of things that has more than one possible ‘value’ – A ‘variable’ is not a constant! Not all observed cases are identical with respect to this value. – Variables imply differences and hence comparability.
Variable Definitions• Here are some more ways of defining ‘variable’: – A variable is a characteristic or value that can change or be changed. – A category or attribute with more than one possible type or value. – A category of things with observed differences or changes. – a quantity that may assume any one of a set of values (Merrian-Webster)
Variables: Cause and Effect• Below are some examples of how two variables may relate causally. We usually designate with an ‘X’ the variable we think is ‘causing’ (‘influencing’, ‘effecting’ etc.) the other variable, which we designate as Y.• X Y• Examples: – Gender (X) is thought to influence occupation (Y) – Religious affiliation (Y) is thought to be influenced by income. – Educational attainment (X) is thought to influence income (Y). – Age (X) is thought to influence attitudes towards using computers (Y) – Income (Y) is thought to be influenced by race (X)
Variables: Independent (X) vs Dependent (Y)• Independent variable (X) = the cause. Variable that influences.• Dependent variable (Y) = the effect. Variable that is influenced by the cause; it is dependent on the cause.• INCA: the INdependent variable is the CAuse.
Directionality• Variables that vary in the same direction have a positive relationship.• Variables that vary in the opposite direction have a negative relationship. – Example: a decrease in employment is associated with a decrease in income: – Even though both variables go down, they vary in the same direction. This is a positive relationship! (-1 * -1 = + 1)
Operational Definitions• Creating an operational definition involves transforming the variables into things that can be observed and measured.• Operational just means ‘working’: you are creating a ‘working’ definition, i.e. one that you can use!
Mean, Median, Mode• Mean is the average: add up the values and divide the result by the number of cases.• Median is the number in the middle so that half of the numbers in the set are above this number and half are below it.• Mode is the number that occurs most frequently.
Quantitative and Qualitative Research1. Quantitative Research – Gathers data that are easily expressed in numbers – Emile Durkheim felt that the goal of sociology was to discover the laws that govern social behavior2. Qualitative Research – Focuses not only on objective nature of behavior but also on its meaning – Max Weber thought that sociology had to be an interpretive science- it must take into account the social meanings/reasons attached to behaviors.