Marketing research chapter 6 smart book
Formula used to calculate sample size when researchers work with small populations
(Specified degree of confidence X variability/desired precision) ^2 X N/(N+n-1)
Probability sampling types
-simple random sampling (pick out of a hat) -systematic random sampling (more methodical than random) -stratified random sampling (divide samples into strata ex- dividing males and females Or by graduate class etc) -cluster sampling (area sampling geographic location Clusters of samples Or some attribute to cluster samples by)
nonprobability sample types
1. Convivence sample (convenient to sample) 2. Judgement Sample (judgement made on samples that they meet the requirements) 3. Quota sample (meet a specific quota need 25% quota met for freshman, sophomore senior etc) 4.snowball sampling (referral) (respondents are chosen and the. They help the researcher identify additional respondents) "Do you know anyone else?"
Steps in Drawing a Stratified Random Sample
1. Divide the target population into homogeneous subgroups or strata 2. Draw random samples from each stratum 3. Combine the samples from each stratum into a single sample of the target population
Identify a difficulty associated with detecting sampling errors in a research study
A census is rarely conducted in survey research
Which of the following is an example of convenience sampling?
A consumer psychology professor interviews his students to measure he success of a new advertising campaign Convenient
Identify an advantage of convenience sampling
A large number of respondents can be interviewed in a Relatively short time
sampling frame
A list of all eligible sampling units
Identify a true statement about determining the sample size for nonprobability samples
A researcher makes subjective, intuitive judgements based on either past studies or the amount of resources available when deriving samples
e=
Acceptable tolerance level of error (%)
A true statement about sampling frames is that ____
Accurate, representative, and current sampling frames are difficult and expensive to obtain
In systematic random sampling, sampling units are selected
By segregating the target population into different subgroups
A research study that includes data about every member of a defined target population is called a
Census
The _ _ _ states that the sampling distribution derived from a simple random sample will be approximately normally distributed
Central limit theorem
A probability sampling method in which units are divided into mutually exclusive and collectively exhaustive sub populations is called
Cluster sampling
A non-probability method in which samples are drawn at the convenience of the researcher is called
Convenience sampling
Steps in developing a good sampling plan
Define the target population Select the data collection method Identify the sampling frames needed Select the appropriate sampling method Determine necessary sample sizes and overall contact rates Create an operating plan for selecting sampling units Execute operational plan
The complete set of elements identified for investigation based on the objectives of a research project is called a __ __ ___
Defined target population
The primary difficulty researchers encounter when using stratified sampling is
Determining the basis for stratifying the target population
Which of the following tasks can be performed by a researchers who understands the basics of a central limit theorem (CLT) ?
Draw representative samples from any target population Obtain sample statistics from a random sample that serve as accurate estimates of the target populations parameters Draw one random sample, instead of many; reducing the costs of data collection More accurately assess the reliability and validity of constructs and scale measurements Statistically analyze data and transform it into meaningful information about the target population
Identify a true statement about cluster sampling
Easy to implement and cost effective
Weird O u thing=
Estimate of the population standard deviation based on some type of prior information
True or false The basic logic underlying optimal allocation is that the greater heterogeneity of a stratum, the fewer the units that would be selected to accurately estimate the true population parameter for the subgroup
False
True or false Nonprobability sampling results are often used by researchers to make statistical inferences about the true population parameters
False These cannot be used to make inferences about true population parameters
True or false Changing respondent behaviors disallow multi source sampling
False This allows multi source sampling
Proportionately stratified sampling
In this sampling method, the strata that make up a larger percentage of the target population are sampled more heavily
Systematic random sampling has become a popular method of drawing samples in research practices because
It can be done quickly and is less expensive
Identify the features of nonsampling error
It can occur at any stage of the research process It occurs due to incorrect question/scale measurements
Which of the following are advantages of quota sampling?
It ensures the identification and inclusion of appropriate subgroups in a survey the sample generated of specific subgroups in the proportions desired by researchers
Which of the following is a disadvantage of systematic random sampling?
It involves the possibility of hidden patterns in the list of prospective participant names that create bias
Identify a disadvantage of simple random sampling
It is difficult to obtain a precise and complete listing of the target population. Elements
Identify a disadvantage of a census
It is more time consuming and expensive than sampling
Which of the following is an advantage of simple random sampling?
It produces unbiased estimates of the characteristics of the target population
A non-probability sampling method in which participants are selected according to a researchers belief that they will meet the requirements of a study are called __ ___
Judgement sampling
The selection of sampling units in non probability sampling is based on the
Knowledge or intuitive judgement of a researcher
_ is sometimes used ins stratified random sampling when no single source can generate a large or low incidence sample
Multi source sampling
N vs n
N= population n= sample
A bias that occurs in a research study regardless of whether a sample or census is used is called
Nonsampling error
In _ method, consideration is given to the relative size of the stratum as well as the variability within the stratum to determine the necessary sample size of each stratum
Optimal allocation sampling
Elements =
Participants
Factors that play a significant role in determining sample sizes with probability designs?
Population variance The degree of precision desired in estimating population characteristic The level of confidence desired in the sample estimate
A nonprobability sampling method in which participants are selected according to pre-specified quotas regarding demographics, attitudes, behaviors, or some other criteria is called ___ __.
Quota sampling
Research panel samples are most often considered _____.
Quota sampling
Factors to determine appropriate sampling design
Research objectives Degree of accuracy Resources Time frame Knowledge of the target population Scope of research Statistical analysis needs
Which of the following is an example of area sampling
Researcher segregating participants based on where they live
In the context of stratified random sampling, which of the following is true of dividing a target population into homogeneous strata?
Researchers have the opportunity to study each stratum and compare strata
_ refers to the selection of a small number of elements from a larger defined target group of elements and expecting that the information gathered from the small group will allow judgements to be made about the larger group
Sampling
A list of all eligible sampling units that are developed by a researcher is called
Sampling frame
The target population elements available for selection during the sampling process are called
Sampling units
_ or referral sampling is a non-probability sampling method in which a set of respondents is chosen by a researcher, and they help the researcher identify additional people to be included in the study
Snowball sampling
Which of the following is true of convenience sampling?
The data are not generalizable to the members of the defined target population.
What is true of cluster sampling
The homogeneous nature of clusters leads to precise sample estimates
A marketing researcher hired by an electronics company wants to identify the impact of the new features of the company's toasters on its sales. She identifies the names of the people who bought the toasters from Jan 2013 to Jan 2014 and sends them a survey The sampling unit in the scenario given above is ____
The people who bought the toasters
Identify the true statements about the factors that play an important role in determining sample sizes with probability designs
The population variance, which is a measure of the e dispersion of the population and it's square root, referred to as the population standard deviation (The greater the variability in the data being estimated, the larger the sample size needed) The level of confidence desired in the estimate (Confidence is the certainty that the true value of what we are estimating falls within the precision range selected) The degree of precision desired in estimating the population characteristic (The acceptable amount of error in the sample estimate) the smaller the desired error, the larger the sample size should be
Which of the following is a feature of judgement sampling
The representativeness of the sample cannot be measured
Which if the following is a feature of judgement sampling?
The representativeness of the sample cannot be measured Since it's based off the researchers judgement on who would be best for study
Identify a rule that is followed when selecting members from a population for the inclusion in probability sampling
The selection of the sampling units should be unbiased
Zb, CL =
The standardized Z value associated with the level of confidence
An inherent limitation of quota sampling
The success of a study is dependent on subjective decisions made by researchers
Random sampling error occurs because
There can be chance variations in the selection of sampling units
Identify true statements about research panel samples
They are quota sampling drawn based on behavioral patterns, demographic quotas, and similar information They are non-probability samples but are considered representative of the target population
disporportionately stratified sampling
This sampling method is used when stratification of the target population produces sample sizes for subgroups that differ from their relative importance to a study
Identify a purpose of quota sampling
To ensure the representation of pre specified subgroups of the population
True or false It is essential to define a target population precisely, which is done in terms of elements, sampling units, and time frames
True
Sign for the true target population mean
Weird upside down u
Given X= defined target population list size And Y= desired sample size Identify the formula for skip interval that is used in systematic random sampling
X/Y
Sign for the percentage value derived from a simple random sample
__ P
Sign for sampling distribution of the mean
__ X
In systematic random sampling, sampling units are selected
according to their position using a skip interval
A form of cluster sampling in which the clusters are formed by geographic designations
area sampling
Sampling is often used when?
conducting a census is impossible or unreasonable
Proportionately stratified sampling
each stratum is DEPENDENT on its size relative to the population
Systematic random sampling is frequently used because
it is a relatively easy way to draw a sample while ensuring randomness
Sign for the size of sample
n
Standardized formula used to calculate the sample size for a simple random sample on a situation where estimates of population proportion are of concern
n= (Z2B, CL) (PxQ/e2)
Formula used to estimate the sample size for a simple random sample when the situation involves estimating a population mean
n= (Z2B, CL) (o2/e2)
Standardized formula used to calculate the sample size for a simple random sample in a situation where estimates of a population proportion are of concern
n= (Z2B, CL) (o2/e2)
Skip Interval Formula
population size/sample size
any type of bias that is attributable to mistakes in either drawing a sample or determining the sample size
sampling error
The blueprint or framework needed to ensure that the data collected are representative of the defined target population
sampling plan
Unlike stratified random sampling, the sampling units in cluster sampling are _____.
segregated into mutually exclusive and collectively exhaustive subpopulations
A probability sampling procedure in which every sampling unit has a known and equal chance of being selected is called
simple random sampling
Disproportionately stratified sampling
size of each stratum is INDEPENDENT of its relative size in the population
Before polling the students in Scion School of Business, a researcher divides all the current students into groups based on their class standing, such as freshman, sophomores, and so on. Then, she randomly draws a sample of 50 students from each of these groups to create a representative sample of the entire student body in the school. Which of the following sampling methods is the researcher practicing?
stratified random sampling
_ involves the separation of the target population into different groups and the selection of samples from each group
stratified random sampling
An inherent limitation of quota sampling is that _____.
the success of a study is dependent on subjective decisions made by researchers
When is snowball sampling used?
when potential members of the population are difficult to identify When the defined target population is unique and small