unit 1 Flashcards
According to the slides, what is the role of statistics?
Statistics is present wherever knowledge is developed.
What two types of research are mentioned in the slides?
The slides mention qualitative and quantitative research.
What are the steps of the research process according to the slides?
The research process includes research question, documentation, hypothesis formulation, study design, data collection, data analysis, and interpretation of results.
How is a ‘population’ defined in the context of data analysis?
A population is defined as all the elements that share the characteristic under study. Examples include people, animals, institutions, or cities.
What is a ‘sample’ and what are its key characteristics?
A sample is a subset of the total number of elements from the population. It must be representative in terms of size and sampling methods.
What are ‘units of analysis’?
Units of analysis are the elements between which some quality is compared, generally the subjects or individuals.
Units of analysis are the things being compared, usually people or subjects.
What is the difference between a parameter and a statistic?
Parameters are values representing quantitative properties of a population, denoted by Greek letters. Statistics are values representing quantitative properties of a sample, denoted by Latin letters.
What are the two main areas of statistics?
The two main areas of statistics are descriptive and inferential statistics.
What is the goal of descriptive statistics?
The goal of descriptive statistics is to summarize a set of information in order to interpret it and draw conclusions. This often includes using graphs, percentages, and means.
What is the purpose of inferential statistics?
Inferential statistics uses probability calculations to estimate, predict, or generalize conclusions about a population based on sample data.
What is a variable in the context of data analysis?
A variable is a feature of the units of analysis that can change or vary between people, over time, or between situations.
What is a constant?
A constant is a modality or value shared by all units of analysis.
What are independent and dependent variables?
An independent variable is a proposed cause or predictor, and the dependent variable is the proposed result or outcome.
How are variables notated in data analysis?
Variables are notated using Latin alphabet letters, such as X, Y, U, or V.
Why are variable values coded numerically for data analysis?
Variable values are always coded numerically for data analysis for
Efficiency: Faster processing and storage.
Compatibility: Many algorithms need numbers.
Calculations: Enables math operations.
Ordering: Logical ranking for ordinal data.
Machine Learning: Models require numerical inputs.
Visualization: Easier to plot and analyze.
What two properties must be ensured when constructing categories for variables?
The categories must have mutual exclusion, meaning each category excludes the others, and exhaustiveness, meaning all values are covered.
What are the three main types of variables according to the slides?
The three main types of variables are qualitative, quasi-quantitative, and quantitative.
What are the two subtypes of quantitative variables?
The two subtypes of quantitative variables are continuous and discrete.
What are the four levels of measurement scales for variables?
The four levels of measurement scales are nominal, ordinal, interval, and ratio.
What is a nominal scale and to what kind of variables is it applied?
A nominal scale is applied to qualitative variables, and the numbers assigned are symbolic labels with no mathematical properties beyond indicating equal or unequal.
What is an ordinal scale, and what is its key characteristic?
An ordinal scale is used for quasi-quantitative variables. It reflects the order or hierarchy among categories, but not the magnitude of difference between them.
What is an interval scale, and what mathematical operations are possible with it?
An interval scale is applicable to quantitative variables, has equal intervals between numbers, allowing for addition and subtraction, but does not have a true zero point.
What is a ratio scale, and what distinguishes it from an interval scale?
A ratio scale is used for quantitative variables and has a non-arbitrary zero point, allowing for all mathematical properties (addition, subtraction, multiplication, and division).
What does the text say about how measurement scales define the attributes or the values?
The measurement scales define the values that are used and not the attributes. The indicator and its values tell us what type of variable it is.
According to the text, what is an example of a variable that uses an interval scale?
Temperature measured in degrees Celsius or Fahrenheit is an example of an interval scale. The origin of zero is not an absolute value.
According to the text, what is an example of a variable that uses a ratio scale?
Weight, income, and unemployment rate are examples of variables using a ratio scale.
What is an example of a variable measured with a nominal scale?
Marital status, city, and treatment received are examples of variables measured with a nominal scale.
What is an example of a variable measured with an ordinal scale?
Educational level, grades, and severity of damage are examples of variables measured with an ordinal scale.
According to the text, what kind of scale is used to measure height above sea level?
Height above sea level is measured using an interval scale.
According to the text, what kind of scale is used to measure height above ground?
Height above ground is measured using a ratio scale.
