Unit 1 Introduction to ADA & Statistics Flashcards
An F -Test is to..
to test for equality of two variances
An independent pooled T-Test is for..
2-sample t-test for non-equal variance
and equal variance
A paired T-Test is for…
Bivariate data. Data for two variables (usually two types of related data)
Types of non-parametric tests
Mann - Whitney, Wilcoxon signed-rank
Types of parametric tests
One-way ANOVA and multicomparison
tests (MCT) aka ‘post-hoc’ tests with fixed effects models
(Class I) and random effects models (Class II)
What is a variable
The property that you measure
Variables can be:
Dependent: The property we are measuring based in our observation
Independent: explanatory or factors in a model
Difference between independent and dependent variables
An independent variable is the factor manipulated to observe its effect, whereas a dependent variable is the outcome or response that is measured. In essence, the independent variable causes a change, and the dependent variable is what is being affected.
What are the types of variables
Qualitative: Categorical variables or attributes.
Quantitative: (or scale in SPSS): measurements, a numerical value is assigned.
Examples of Qualitative variables
Ranked or ordinal: 0-no pollution, 5-polluted, maturity.
Nominal or non-ordinal: Lake name, varieties.
Binary (a type of nominal): yes/no, male/female, in/out
Examples of Quantitative variables
Continuous: Called ratio variables by SPSS. Infinite number of values between two points. Eg. length, weight.
Discrete: Discontinuous or meristic. Observations exist on a limited no. of values. Eg. No. of teeth, No. of spots.
What is qualitative data
Category or nominal data:
Descriptive, non-numerical.
Gender, species, blood groups
What is quantitative data
Values. So counts or measurements used to describe values.
is either,
Discrete - Count data
Continuous - measurement data (Ratio 0 ref point/Interval no true 0)
