Data Collection and Sampling Methods Flashcards
Methods of Data Collection:
Observation
Interview
Questionnaire
Seeks to ascertain what people think and do by watching them in action as they express themselves in various situations and activities.
Observation
Instead of writing the response the interviewee subject gives the needed information verbally face-to-face relationship.
Interview
Provides speedy and simple technique gathering data about groups of individuals scattered in a wide and extended field.
A questionnaire form is sent usually by post / online
Survey Questionnaire
Sampling Techniques
- Probability Random Sampling
- Non-Probability Non-Random Sampling
Start with a complete sampling frame of all eligible individuals from which you select your sample. (unbiased)
Probability Sampling Method
Probability Sampling Method
- Simple Random
- Systematic Sampling
- Stratified Sampling
- Clustered Sampling
Each individual or unit in the population has an equal chance of being selected. Selection is done randomly. Ensuring unbiased representation.
using methods like a lottery system or a random number generator
Simple Random Sampling
A method where elements are selected from an ordered population at regular intervals. The first sample is chosen randomly within the first interval, and subsequent samples follow a fixed pattern.
(e.g., every 5th or 10th individual).
Systematic Sampling
Population is divided into distinct subgroups (strata) based on shared characteristics
(e.g., age, income level, education).
Stratified Sampling
Population is divided into occurring groups (clusters).
(e.g., schools, neighborhoods, or companies. )
Clustering Sampling
All members of the selected clusters are surveyed
one-stage cluster sampling
random subset of individuals within selected clusters is surveyed
two stage cluster sampling
Not all members of the population have an equal chance of being selected. Instead, selection is based on subjective judgment, convenience, or specific criteria set by the researcher.
Non-Probability Sampling
Used in exploratory research, qualitative studies, or when probability sampling is impractical due to resource constraints.
Non-Probability Sampling
Non-Probability Sampling
- Convenience Sampling
- Quota Sampling
- Purposive Sampling
- Snowball Sampling
Participants are selected based on their availability, accessibility, and willingness to participate rather than random selection.
Convenience Sampling
Used in pilot studies, exploratory research, or when time and resources
Convenience Sampling
Researchers deliberately selected individuals who are most relevant to the researcher topic based on predefined criteria, expertise, or specific characteristics.
Purposive Sampling
Commonly used in qualitative research.
Purposive Sampling
Researchers divide the population into subgroups (quotas) and select participants from each subgroup to ensure representation based on characteristics like age, gender, or income. The selection process is not random, so not all population members have an equal chance of participating.
Quota Sampling
Existing participants recruit future participants from their network, particularly useful for studying hard-to-reach or specialized populations.
Snowball Sampling
Starts with few known individuals who refer others, creating a chain of referrals.
Snowball Sampling
Methods in Data Presentation
- Textual Method
- Tabular Method
- Graphical Method
