Search
Create
BUS 367 FINAL Ch. 12 Sample Designs & Procedures
STUDY
Flashcards
Learn
Write
Spell
Test
PLAY
Match
Gravity
Terms in this set (44)
sampling is a critical part of the marketing research process
...
in the end, sampling does much to determine how realistic marketing results will be and to what extent they can predict outcomes of marketing decisions
...
sample
subset of some larger population that researchers observe or measure in some way in an effort to estimate what the entire population is like
population
any complete group of entities that share some common set of characteristics
population element
individual member of the population
census
an investigation involving measurement of all the individual elements that make up a population
a sample on occasion may even be more accurate than a census
...
stages in the selection of a sample
1. define the target population
2. select a sampling frame
3. determine if a profitability or non profitability sampling method will be chosen
4. plan procedure for selecting sampling units
5. determine sample size
6. select actual sampling units
7. conduct fieldwork
sampling frame
list of elements from which a sample may be drawn
also called working population
sampling frame error
occurs when certain sample elements are excluded or when the entire population is not accurately represented in the sampling frame
reverse directory
similar to a telephone directory except that listings are by city and street address, or by phone number rather than by alphabetical by last name
useful when a retailer wishes to survey only a certain geographical area of city
the elements of a population must be selected according to a specified procedure when sampling
...
sampling unit
single element or group of elements that is eligible for selection via the sampling process
primary sampling
first stage of sampling
secondary sampling
second stage of sampling
tertiary sampling
third stage of sampling
an estimation made from a sample is not the same as a census count
...
random sampling error
difference between the sample result and the result of an accurate census
occurs because of chance variation in the selection of sampling units
refers only to statistical fluctuations that occur because of chance variations in the elements selected for the sample
a function of sample size
as sample size increases, random sampling error decreases
systematic (non sampling) error
result from non sampling factors, primarily the nature of a study's design and the correctness of execution
panels are not perfect
...
panel sampling frames may contain a high proportion of respondents who simply like to fill out questionnaires or give their opinion
...
as the concern for representatives increases, the more steps the researcher must take to ensure that the sampling units do indeed represent the population
...
opting in
respondents decides to participate in a research project on his/her own response and provide data for the researcher
it is important NOT to send unauthorized emails to respondents
...
random sampling errors and systematic error associated with the sampling process may combine to yield a sample that is less than perfectly representative of the population
...
probability sampling
every member in the population has a known, non zero probability of selection
the simple random sample, in which each member of the population has an equal probability of being selected, is the best known probability sample
...
the likelihood of any panel member being selected as a potential respondent is fixed, nonzero, and known
...
non probability sampling
units of the sample are selected on the basis of personal judgement or convenience
the probability of any particular member of the population being chosen is unknown
convenience sampling
sampling by obtaining people or units that are conveniently available
judgement (purposive) sampling
non probability sampling technique in which an experienced individual selects the sample based on his or her judgement about some appropriate characteristics required of the sample member
quota sampling
ensures that the various subgroups in a population are represented on pertinent sample characteristics to the exact extent that the investigators desire
advantages- speed of data collection, lower costs, and convenience
snowball sampling
involves using some process for selecting a few initial respondents and then uses those respondents to seek out additional respondents
all probability sampling techniques employ chance selection procedures
...
simple random sampling
ensuring that each element in a population has an equal chance of being included in a sample
ex.) drawing a name from a hat, raffle tickets
systematic sampling
starting point is selected by a random process and then every nth number on the list is selected
although systematic sampling is not actually a random selection procedure, it does yield random results if the arrangement of the items is not in some sequence corresponding to the interval in some way
stratified sampling
simple random subsamples that are more or less equal on some characteristic are drawn from within each stratum of the population
reasoning- to obtain a more efficient sample than would be possible with simple random sampling
ensures that the sample will accurately reflect the population on the basis of the criterion used for stratification
proportional stratified sample
the number of sampling units drawn from each stratum is in proportion to the population size of the stratum
disproportional stratified sample
the sample size for each stratum is not allocated in proportion to the population size but is dictated by analytical considerations, such as variability in stores, sales, volume
as variability increases, sample size must increase to provide accurate estimates
...
cluster sampling
economically efficient sampling techniques in which the primary sampling unit is not the individual element in the population but a large cluster of elements
clusters are selected randomly
area sample
most popular type of cluster sample
multistage area sampling
cluster sampling approach involving multiple steps that combine some of the probability techniques already described
geographic areas are randomly selected in progressively smaller units
what is the appropriate sample design?
degree of accuracy
resources- cost
time
advance knowledge of the population
national vs. local project
;