Ch. 5 Survey Research Flashcards
Population
a set of all cases of interest
Sample
a subset of the population used to represent the entire population
Element
each member of a population
Sampling frame
list of the members of a population
- characteristics of participants in sample should be similar to those of the entire population
Biased sample
occurs when characteristics of the sample differ systematically from those of the population
- samples can overrepresent or underrepresent a segment of a population
Selection bias
occurs when a researcher’s procedures for selecting a sample result in one or more segments of the population being under - or overrepresented
Response-rate bias
occurs when individuals selected for the initial sample do not complete and return the survey (lack of interest, worried about privacy, don’t have time)
Ways to increase response rate
- questionnaire has a personal touch
- responding requires minimal effort
- topic of survey is interesting to respondents
- respondents identify with organization or sponsor of survey
Nonprobability sampling
no guarantee each member of population has an equal chance to be in sample
connivence sampling
researcher selects individuals who are available and willing to respond to the survey (magazine surveys, call-in radio surveys)
Probability sampling
all members of population have an equal chance of being selected for the survey
simple random sample: random digit dialing
stratified random sample: equal number of freshman, sophomores, juniors, seniors
Four survey methods
mail surveys, internet surveys, telephone surveys, personal interviews
Mail surveys
advantages: quick, convenient, self-administered, best for highly personal or embarrassing topics
disadvantages: problem of response rate, little control over how people respond to the questions
Personal interviews
advantages: researchers gain more control over how survey is administered, interviewers can seek clarification of answers, ask questions
disadvantages: possible interviewer bias, interviews are costly; interviewers must be highly motivated, carefully trained, supervised
Telephone interviews
advantages: complete brief survey efficiently and with greater access to population, random-digit dialing to select random samples, supervise interviewers easily
disadvantages: no phone or multiple phone numbers, willingness to answer questions on phone, changes in survey questions and responses
Internet surveys
advantages: efficient, low-cost, potential for very large samples, samples can be very diverse and access typically underrepresented samples
disadvantages: access to internet, willingness to respond, lack of control over research environment
Cross-sectional survey design
select sample from one or more populations at one time
- choose population of interest
- use probability sampling or convenience sampling
- respondents complete a survey one time
Successive independent samples design
a series of cross-sectional designs over time
- a different sample from the population completes the survey each time (can see how a population changes over time)
Longitudinal survey design
same sample of individuals completes the survey at different points in time
- can assess how individuals change over time ( and populations)
Questionnaires
most frequently used to collect survey data, measure different types of variables (demographic variables using checklists, preferences and attitudes)
Guidelines for writing survey questions
Choose how participants will respond
- free-response (open ended)
- closed-response (multiple choice, true-false)
Use simple, familiar vocabulary; keep questions short
Write clear and specific questions
- avoid double-barreled questions
- avoid conditional phrases at the end of sentences
- avoid leading questions
- avoid loaded )emotion-laded) questions
Ordering of questions
- self-administered questionnaires (most interesting questions first)
- use funnel questions (start with general questions then move to more specific ones)
- use filter questions (direct respondents to appropriate questions)
Test-retest reliability
- administer measure two times to same sample
- individuals’ scores should be consistent over time
- a high correlation between the two sets of scores indicates good test-retest reliability (r > .80)
- individuals’ scores need not be identical each time, only same place in the distribution of scores
How to improve reliability?
- more items
- greater variability among individuals on the factor being measured
- testing situation free of distractions
- clear instructions
a measure can be reliable but not valid
Convergent validity
extent to which two measures of the same construct are correlated