Statistics
How we make sense of the world through data which happens through statistical analysis.
Descriptive Statistics
Procedures for organizing and summarizing data so that the important characteristics of the data can be described and communicated.
Ex…Mean, Standard Deviation, range
Inferential Statistics
Procedures for determining whether the sample data are representative of a particular relationship or allow you to draw conclusions about your data that can be applied to the wider population.
Ex…t-test or regression
Population Parameter
Number that characterizes the population.
Target Population
The entire group of interest that we are wish to better understand.
Study Population
All members of the group that we are studying to understand the target population.
Sample Statistic
Number that characterizes the sample.
Sample
Statistical information that we gather related to the study population that we hope is representative of the target population.
Variables
Characteristic, number, or quantity that can be measured or counted and that can take on different values.
Indepedent Variable (IV)
Another name for predictor variable as it value does not depend on any other variable.
Dependent Variable (DV)
Another name is outcome variable as the value does depend on another variable (e.g. independent variable).
Confounding Variable
A variable that affects both the dependent variables and the independent variables and causes distortion of the effects of the study.
Categorical Data
Qualitative
1. Nominal Data
2. Ordinal Data
Discrete or Continuous Data
Quantitative
1. Interval Scaled Data
2. Ratio Scaled Data
Nominal Scales
Observations are labeled and categorized - No True Zero
(Dichotomous - where there are two categories only)
Ex…Numbers assigned to runners
7, 8, 9
Ethnicity
Ordinal Scales
Ranking observations in terms of size or magnitudes
No True Zero
Ex….Rank orders of winners
1st, 2nd, 3rd
Ranks of Professors
Interval Scale
EQUAL difference (or intervals) between numbers on the scale reflecting differences in magnitudes - No True Zero
Ex…Performance rating on a scale
8.2, 9.1, 9.6
GPA
Ratio Scale
Ratio of numbers that do reflect ratio of magnitudes. This scale has an absolute zero point. - True Zero
Ex…Time to finish in
15.2, 14.1, 13.4
