exam 2 Flashcards
diminishing returns in sampling
after a certain sample size, increases provide minimal additional accuracy
stratified sampling
dividing a population into subgroups and sampling from each to ensure representation across all groups
confidence level
a 95% confidence level means 95% of survey repetitions would fall within the
margin of error, if a study were replicated the same results would be returned
convenience sampling
who the researcher has easiest access to, convenience samples may not represent the population accurately
probability sampling
gives each population member an equal chance of being selected
efficiency in sampling
sampling helps researchers make inferences about a population without surveying everyone
quota sampling
ensures the sample reflects certain population characteristics without random selection
incidence rate
represents the proportion of the general population meeting the survey criteria
stratified sampling
ensures each region or subgroup is proportionally represented
snowball sampling
effective for hard-to-reach populations by using current participants to recruit others
sample size determinants
survey length does not directly affect sample size; confidence level, margin of
error, and population size do
referrals
snowball sampling involves using referrals from current participants to reach more respondents
known selection
in probability sampling, every population member has a known selection chance,
ensuring representativeness
non-probability sampling
less representative, limiting generalizability of results
survey length
long, complex surveys can reduce response rates, participants are less likely to complete them
mail surveys
mail surveys generally have lower response rates compared to online surveys
incentives
offering incentives can encourage participants to complete the survey, boosting response rates
cost-effective survey
online surveys are more cost-effective due to lower distribution and collection costs
confidentiality
restricting access to personal data to
authorized personnel only
integrated survey tools
online survey software offers tools to create, distribute, and analyze surveys
anonymity
online surveys are preferred for sensitive topics as they allow anonymity and reduce bias
high response rates
improves data reliability and better reflect the population’s views
reducing survey bias
randomizing questions and using neutral language helps reduce survey response
bias
ethical data collection
ensures participant confidentiality and informed consent
survey invitations
should be clear, concise, and engaging to motivate participants
branching logic
customizes the survey path based on prior responses, improving relevance and flow
self-selection bias
occurs when only certain respondent types participate by volunteering, skewing results
reminder frequency
no more than two reminders to increase response without overwhelming participants
leading questions
leading questions can create implementation bias by suggesting specific responses
identifying most common responses
the mode represents the most frequently selected response in a survey dataset
data cleaning
correcting errors and inconsistencies in datasets before analysis
variation in data
measures of spread, like standard deviation, show how responses differ from the mean
top-box scoring
using the percentage of respondents selecting the highest rating option
categorizing open-ended responses
coding organizes open-ended responses into themes for quantitative analysis
top 2-box score
adding the percentages for the two highest rating categories, showing positive sentiment
median with outliers
the median is less affected by outliers than the mean, making it more
representative with skewed data.
comparative analysis by demographic
cross tabulation that helps compare survey responses across demographic groups
clustering
standard deviation indicates clustering around mean values
weighing data
corrects for overrepresented or underrepresented demographics, such as age or gender, to better represent the population
summarizing typical values
measures like mean, median, and mode help summarize the central tendency in
a dataset
segmenting by demographics
cross tabulation (data tables that “cross” results) by demographics, revealing information specific to different groups (subset)
describing categorical responses
percentages that summarize categorical data, for reporting on proportions
quantifying open-ended responses
coding open-ended responses categorizes them for easier quantitative analysis
purpose of inferential statistics
inferences about a population based on sample data
null hypothesis
assumes no difference exists between groups in the target population
p-value with significance level
if a p-value is lower than the significance level, it suggests a statistically
significant effect
type I error
occurs when a true null hypothesis is incorrectly rejected (false positive)
t-test
used to compare mean scores between two groups on a continuous
variable
correlation coefficient close to 1
indicates a strong positive relationship
between variables
p-value in hypothesis testing
The p-value indicates the probability that the null hypothesis is true in the
population
ANOVA
used when comparing mean scores across three or more groups
alternative hypotheses (p-value with null)
If p-value > alpha, fail to reject the null hypothesis, no significance is found
paired t-test
to test mean scores between two groups, represented in pairs
example: comparing related scores from the same respondents
type II error
happens when a false null hypothesis is not rejected (false negative)
conjoint analysis
identifies which combinations of features are most valued by customers
linear regression
quantifies relationships between dependent and independent
variables, used for forecasting
best use for chi-square test
chi-square test is best suited for comparing categorical variables, like product preference by region
multiple regression
examines multiple factors together to predict an outcome, such as sales
margin of error
how uncertain a measurement or estimate is, and how confident we can be in its accuracy
