Research Process & Basic Concepts of Statistics Flashcards
(41 cards)
Key steps in the research process
- Define the research problem, the target phenomenon, what is know, what is gap.
- Develop a research plan.
- Theoretical framework
- Collect data.
- Analyze data.
- Report findings
Types of Variables:
Nominal Variables
Ordinal Variables
Interval Variables
Ratio Variables
Nominal Variables
Categories without a specific order (e.g., gender, nationality).
- Distinct categories
- No overlapping categories
- Similar/different
- No ranking is implied
- Two categories (e.g. gender) and multiple categories (e.g. nationality)
Ordinal Variables
Categories with a defined order, but no consistent difference between categories (e.g., satisfaction level: low, medium, high).
- Ranking is implied (either natural or defined)
- Does not account for the amount of differences between the categories
- Order of goodness, opinion poll …
- E.g. military ranks, fully agree ↔ fully disagree
- Note! For example opinions measured on a Likert-scale is an exception, because
although the variable is measured on ordinal scale, calculating means is allowed
Interval Variables
Numeric scales with equal intervals but no true zero (e.g., temperature in Celsius).
- Numeric variables
- Ordered scale in which the difference between measurements is a meaningful quantity
- Variables have measurement units
- Additions and subtractions are allowed
- Does not involve a true zero point where the characteristic ”disappears”
- E.g. temperature in °C or F or year of birth or pH-value (0-14)
Ratio Variables
Numeric scales with equal intervals and a true zero (e.g., height, weight, income).
- Ordered scale
- Involves a true zero point
- Can be multiplied by a constant
- E.g. length, weight, age
Identify variables in real-world situations:
Example 1: Age of participants in a survey
Ratio Variable (It has a true zero and the intervals between values are meaningful).
Identify variables in real-world situations: Example 2: Customer satisfaction levels: “Very Dissatisfied,” “Neutral,” “Very Satisfied.”
Answer: Ordinal Variable (There is a clear order, but the differences between levels are not measurable).
Identify variables in real-world situations: Example 3: Types of cuisine (Italian, Chinese, Mexican) ordered in a restaurant
Answer: Nominal Variable (There is no specific order in the categories).
Identify variables in real-world situations: Temperature measured in degrees Fahrenheit.
Answer: Interval Variable (It has equal intervals, but no true zero).
Population is
consists of all the items or individuals about which you want to draw a conclusion (e.g. personnel, products, habitants …)
Sample is
the portion of the population selected for analysis
Measuring
means linking numerical values to research objects
Observation unit i.e. statistical unit is
a single research object (e.g. person, product, habitant …)
Observation is
the measured result (value) that is related to one research object
A variable is
a characteristic of an item or
an individual. In empirical research variables are measured
Variables are classified
as either being quantitative i.e. numerical (such as a person’s
weight) or qualitative i.e. categorical (such as a person’s sex).
Numerical variables are further classified as
having either discrete or continuous values. Continuous variables are measured and can have any value within a range, while discrete variables are counted and can only take distinct, whole number values.
Continuous variables
Continuous variables can take an infinite number of values within a given range. These variables are measurable and can include any value, including decimals and fractions.
Examples:
Height (e.g., 170.5 cm)
Weight (e.g., 68.2 kg)
Temperature (e.g., 36.7°C)
Characteristics:
Can take any value within a certain range.
Often result from measurements.
Between any two values, there can always be another possible value (e.g., between 2 and 3, there is 2.5).
Discrete variables
Discrete variables have numerical values that arise from a counting process or just
separate different values from each other. (e.g. number of things) and can only take specific, distinct values, usually integers. These values are countable and have a clear distinction between one value and the next.
Examples:
Number of children in a family (e.g., 2, 3, 4)
Number of cars owned (e.g., 1, 2, 3)
Number of students in a class (e.g., 25, 26, 27)
Characteristics:
Can only take specific values, no fractions or decimals.
Often result from counting.
There are gaps between the possible values (e.g., you can have 2 children or 3 children, but not 2.5 children).
Delimitations
- Exact delimitations should be defined for the
study (target phenomenon is usually broad) - In delimitations you define what is included in the
research and what is left outside. - Theoretical delimitations: you explain which
theoretical concepts / theoretical models you will
use in your study. - Empirical delimitations: what is included in
empirical part; a specific case‐company, or
specific customer segment, or specific market. - Everything needs to be justified.
It’s crucial to narrow down the research topic by establishing theoretical and empirical delimitations to focus on specific aspects of the phenomenon.
Example from the Lecture: The lecturer provided an example where a supermarket might focus only on student customers, excluding other types of customers as part of the empirical delimitation.
Variables in figure
Qualitative
- Nominal (age, nationality)
Quantitative
- Descrete (number of kids)
- Ordinal scale (amount of students, military ranks)
- Continuous (weight)
- Ordinal scale (pain level on a scale from 0 to 10)
- Interval Scale (numerical, no zero: Tempetrature)
- Ratio Scale (numerical, with zero: Age)
which is the measurement level: age
Age:
Measurement Level: Ratio
Explanation: Age is measured on a numeric scale with a true zero (0 years means no age). It allows for meaningful comparisons and calculations (e.g., someone who is 20 years old is twice as old as someone who is 10).
which is
the measurement level: amount of students
Amount of Students:
Measurement Level: Ratio
Explanation: The number of students is a countable quantity with a true zero (0 students means there are no students). It allows for operations such as addition and multiplication, making it a ratio variable.