QM -Midterms Flashcards
- Used to filter individuals from a population and create samples
Probability
o – random selection & Most used
Simple random sampling
o sampling – population -> groups(strata)
Stratified random
o –main segment -> clusters (geographic segmentation) univ -> colleges
Cluster sampling
o – first = random, ff = fixed interval(N/n)
Systematic sampling
WHEN TO USE PROBABILITY SAMPLING
o You want to reduce the sampling bias
o The population is usually diverse
o To create an accurate sample
Advantages of Probability
o It’s cost-effective
o It’s simple and straightforward
o It’s non-technical
Can avoid sampling errors (unexpected results)
- Not all of them has equal chance of being chosen
Non-probability
o – elements chosen = proximity to the researcher, quick and easy implementation
Convenience sampling
o – ^same, r = choose 1 element / sample group
Consecutive sampling
o – elements = knowledge of traits & pers. -> strata
Quota sampling
o – used when audience = rare
Snowball sampling
o – samples = r experience & skills
Judgmental sampling
WHEN TO USE NON-PROBABILITY
o Particular trait/characteristic exist in the population
o Aim at conducting qualitative research, pilot studies or exploratory research
o Have limited time to conduct research or budget constraints
o In-dept analysis is needed
o Get specific results
Advantages of Non-probability sampling
o More conducive and practical
o Faster and more cost-effective
o – research method used for collecting data
Survey
- – data -> same categories
Nominal
- – measure variable in ranking, meaningful insights un. responses
Ordinal
- – measure variable w/ equal interval, temp & time
Interval
- – comparison in ratios, %, ave,
o Great for research in fields like science, engineering, and finance, where you need to use ratios, percentages, and averages to understand the data.
Ratio
- – effective survey dist., widely used
- – responses are much higher using this
Buy respondents
- – ^ responses = close proximity to the brand
Embed survey on a website
- : social media -> survey aids = ^ responses
Social distribution
- : store the URL for the survey. Print & publish
QR code
- : quick and time-effective way to collect a high number of responses.
SMS survey
- ’ is a market research term
o number of individuals included in conducting research.
Sample size
- is the process of choosing the right number of observations or people from a larger group to use in a sample.
Sample size determination
– how many people fit your demographic, total number
Population Size
- The ________ tells you how sure you can be that your data is accurate. %
confidence level
- tell you how far off from the population means you’re willing to allow your data to fall.
Confidence intervals
- A ________ describes how close you can reasonably expect a survey result to fall relative to the real population value.
margin of error
- is the measure of the dispersion of a data set from its mean. It measures the absolute variability of a distribution. ^ dispersion or variability = = the standard deviation + ^ magnitude of the deviation.
Standard deviation
- aka data scrubbing or data cleansing.
- Ensures the use of the highest-quality data to perform the analysis.
- ”Garbage in, garbage out” George Feuchsel
- 80/20 Dilemma: 80% of research time is finding, cleaning, and reorganizing huge amounts of data. Only 20% is spent on actual data analysis.
Data Cleaning
o Also known as Exploratory Data Analysis (EDA)
o Developed by John Tukey in the late 1970s
o an approach used to better understand the data through quantitative and graphical methods
Discovering Data