1-Variables, scores and values Flashcards
What are variables?
Physical or abstract attributes or quantities that we wish to measure
What is a score ?
The value that an individual has on a particular variable.
Gurnsey, Rick. Statistics for Research in Psychology (p. 5). SAGE Publications. Édition du Kindle.
What are quantitative variables?
Variables whose values are numbers
What are Qualitative variables ?
Variables whose values are qualities
What constitutes a Ratio Scale?
1) Absolute zero, because with compare the distance of the two values with the absolute zero
2) A unit of measurement
What are discrete quantitative variables?
They have fixed values, so intergers or whole numbers
What are quantitative continuous variables?
IThey have values that are real numbers
What constitutes an Interval Scale ?
1) Unit of measurement
2) NO abosulte zero
What types of variable are measured on a nominal scale ?
1) Qualitative
2) Discrete
3) Unordered categories
What are Ordinal Variables?
A variable with properties of both quantitative and qualitative
What constitutes an ordinal scale ? Give an example
1) Measure qualitative and discrete variables
2) Natural ordering, but No unit of measurement
ex: Letter Grade (A+, A, A-, etc.)
Give the Stevens Hierarchy of Scales
- Ratio scales
- Equal interval squale
- Ordinal scales
- Nominal scale
What is a psychocologial construct ?
An hypothetical attribute that explains some types of behavior
What is an operational measure?
A tool used to measure psychological construct
What is validity?
When we measure what is supposed to be measured
What is reliability?
When the device give similiar or identical measurements every time it is applied to the same object
What is measurement error?
Everytime something is measured, there is going to be a slighty different score
What is a population?
Collection of individuals that share a common caracteristic of interest
What is a sample?
A subset of the population
What is a parameter?
A numerical characteristic of a population
What is a statistic?
A numerical characteristic of a sample
What are inferential statistics?
The act of infering a population paramaters from a sample statistics
What are descriptive statistics?
To describe a collection of scores, without inferring anything about a population parameters
What is simple random sampling ?
All members of a population have an equal chance of being selected in a sample
